I am not an archer and don't use a Juju so take everything I say with a grain of salt, especially about the assumed stats of archers. Please let me know if you feel like the assumed stats are not reasonable.
A lot of people are satisfied when they get 100% crit chance (CC) and they do not try to get more. However, getting 200 CC with overload 5 increases the damage by 50%. CC is really worth to go for, even if it requires you to sacrifice some crit damage (CD) and strength (S), the 50% damage increase from overload makes up for it. Even with a terminator that divides your CC by 4, there are unexpected ways to increase your dps, such as reforging epic accessories to unpleasant. (Accessory reforging guide for terminator HERE.)
I will only consider the damage inside dungeons.
I will not consider bonus attack speed reforges, only the damage reforges. Reaching the maximum fire rate is very important and should be prioritized over reforging to CC. (Some analysis of the fire rate of shortbows can be found HERE.)
==================================
Some Maths:
It is pretty well known that the damage is proportional to (S+100)*(CD+100). Between 100 and 200 CC the probability to deal regular damage is (200-CC)/100 and the probability to deal 50% more damage is (CC-100)/100. The expected damage is hence proportional to 1*(200-CC)/100+1.5*(CC-100)/100, which is proportional to (CC+100). This is the exact same scaling as what we see in the case of S and CD.
So the scaling of damage with S, CD and CC between 100 and 200 CC is:
(S+100)*(CD+100)*(CC+100)
Using this formula, you can easily compare reforges by plugging in what stats you would have with each of them and the one that gives a higher number is the better for expected damage.
==================================
Increasing CC:
The best armor reforge for CC is ancient which is also the best for S and CD so this is an easy choice and there is nothing new here in this regard.
For Juju reforge, people usually use spiritual (83 S+CD, 12 CC) or precise (75 S+CD, 13CC). A possibility to get a lot of CC is to use hasty instead (15 S, 50 CC). Even though CC doesn't scale with catacombs level, the 5 stars increase it by 50%. If a player has 143 CC with spiritual reforge, they will have 200 CC with hasty. This increases the dps by 23.5%. In the meantime the player loses 68 S and CD in total, which is increased by the player's catacombs level and the stars on the bow. Here are some estimations on how much damage loss this is for players on different levels, let me know if you feel like those numbers are not reasonable:
Catacombs 15, 1000 S, 1000 CD -> 15% damage loss
Catacombs 20, 1400 S, 1400 CD -> 14% damage loss
Catacombs 25, 2000 S, 2000 CD -> 12% damage loss
Catacombs 30, 2500 S, 2500 CD -> 10% damage loss
So the damage gain from overload is more than the damage loss from the less S and CD when reforging from spiritual to hasty. It is worth it to reforge the Juju to hasty if that helps to get closer to 200 CC.
There are only two accessory reforges that can give CC: unpleasant for all rarities and shaded for legendary and mythic accessories. Strong is often used for legendary and mythic accessories as it gives the most S and CD combined, but shaded gives 1 and 2 less of these respectively for the two rarities and gives 1 CC in exchange. This will always be better for damage than strong if the player has less than 200 CC. For common to epic accessories, many people use shaded as that is the reforge that gives the most S and CD combined. However, unpleasant gives CC for these and hence it could be worth it to reforge these accessories to unpleasant. The easiest way to choose between these is to just use the formula presented before, but here are some useful numbers:
Common | Uncommon | Rare | Epic | Legendary | Mythic | |
1000 S, 1000 CD | Unpleasant is better under 120 CC | Shaded is better | Shaded is better | Shaded is better | Shaded is better | Shaded is better |
1500 S, 1500 CD | Unpleasant is better | Unpleasant is better under 129 CC | Shaded is better | Unpleasant is better under 191 CC | Shaded is better | Shaded is better |
2000 S, 2000 CD | Unpleasant is better | Unpleasant is better | Unpleasant is better under 171 CC | Unpleasant is better | Shaded is better | Shaded is better |
2500 S, 2500 CD | Unpleasant is better | Unpleasant is better | Unpleasant is better | Unpleasant is better | Shaded is better | Unpleasant is better under 136 CC |
3000 S, 3000 CD | Unpleasant is better | Unpleasant is better | Unpleasant is better | Unpleasant is better | Unpleasant is better under 107 CC | Unpleasant is better under 182 CC |
3500 S, 3500 CD | Unpleasant is better | Unpleasant is better | Unpleasant is better | Unpleasant is better | Unpleasant is better under 140 CC | Unpleasant is better |
When no CC is specified under which unpleasant is better, it is better until 200 CC, the maximum useful value of CC is reached.
As it can be seen, it is often worth it to reforge a lot of accessories to unpleasant and get high CC.
Only reforge non-dungeon accessories for CC. The stats from dungeon accessories are scaled with catacombs level, but it doesn't increase its CC. Hence players would lose a lot more stats by reforging dungeon accessories to CC than by reforging non-dungeon accessories and it is most likely never worth it (exceptions are shaded legendary and mythic accessories that barely sacrifice any S and CD for the CC).
==================================
Reforging Order:
To lose as little A and CD while reforging to reach 200 CC, use this order:
Shaded legendary accessories
Hasty Juju (catacombs 0-4)
Shaded mythic accessories
Hasty Juju (catacombs 5-37)
Unpleasant common accessories
Hasty Juju (catacombs 38-40)
Unpleasant epic accessories
Hasty Juju (catacombs 41-42)
Unpleasant uncommon accessories
Hasty Juju (catacombs 43-50)
Unpleasant epic accessories
To maximize your damage, follow this list until you reach 200 CC or an element that is not worth it with your stats.
==================================
Examples:
Early-mid game player:
catacombs 20, 100 CC, 1500 S, 1500 CD -> (S+100)*(CD+100)*(CC+100)=512*10^6
4 legendary accessories strong -> shaded: 104 CC, 1492 S, 1504 CD
juju spiritual -> hasty: 161 CC, 1458 S, 1361 CD
12 common accessories shaded -> unpleasant: 173 CC, 1434 S, 1325 CD
The rest is not worth it with these stats -> (S+100)*(CD+100)*(CC+100)=597*10^6
The damage increased by 16.6%.
Late game player:
catacombs 35, 120 CC, 3000 S, 3000 CD -> (S+100)*(CD+100)*(CC+100)=2114*10^6
7 legendary accessories strong -> shaded: 127 CC, 2986 S, 3007 CD
10 mythic accessories strong -> shaded 137 CC, 2946 S, 3027 CD
juju spiritual -> hasty: 194 CC, 2895 S, 2810 CD
6 common accessories shaded -> unpleasant: 200 CC, 2883 S, 2792 CD
200 CC is reached -> (S+100)*(CD+100)*(CC+100)=2588*10^6
The damage is increased by 22.4%.
==================================
TL;DR: Between 100 and 200 crit chance, the damage of a juju shortbow with overload 5 has the same scaling with crit chance as with strength and crit damage. Since people have much less crit chance than the other two, it is worth to sacrifice a lot of those to get more crit chance, up to 200. Follow the list in the "Reforging Order" section to maximize your damage.