If that's the case, it's very sad. I heard that they said that quantomas or someone else got part of the code from 3.0. Not from 3.1, but specifically 3.0. Maybe that's the reason?
As I wrote to mrHalfer above, quantomas took 3.1 as a basis and trimmed it. It's unlikely that he started with 3.0. The only explanation for the non-working 3.1 scripts is that his cuts disabled their support.
I heard that in 5.5, the experience gain was simplified at higher levels. Or are there no other changes there, besides those mentioned above?
Well, what was mentioned above may include many things. Tweaked parameters and cut conditions, there may be levels and other things too. It will take time and the help of forum gurus to figure everything out. Plus, in 5.5, a lot is done through Lua scripts. I would say a large part of it.
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It seems like this is the optimal and constructive solution to the problem. Did I understand correctly that in the end we will get 3.1 + EE (smart AI, but normal, in terms of time, turn speed)?
That's exactly what I meant.)