Arelith

I've noticed an issue with GSF Trans and stacking zoo buffs. Occasionally I will roll double 1s and instead of getting the full +6 to a stat I am just getting +5 and have to cast again. Since each cast should be providing 1d4+2 this should be impossible. Not sure if this is a known issue or if there's a workaround.

I've noticed this too. Sometimes I will have to cast the same zoo buff three times in order to get the full bonus. That should never happen, based on the math.

If I had to guess, the 1d4 is coded as cumulative and the +2 applies fresh to each cast. Not sure if that is intentional or not.

The stacking of several casts does not include the GSF-bonus - so you get:
1d4+1 two times
Then add the GSF bonus

Don't know if that is the intention, but I've been explained this is how it works.

The above is how it works, yes.

Each cast rolls the 1d4. The flat bonus is separate. If you cast twice and get 1 twice, you would get

1/1d4 +1/1d4 + 2 for a total of 4.