Let's explain a few things.
1) In
RaR AI will
not deforest Plots that have Forrests with
Bonus Ressources that need Forrest.
(e.g. Deer, Lumber, Giant Trees ...)
2) I also implemented
new Distribution Mechanisms for AI considering Strategic Goods like Lumber, Stone, Weapons, ...
(So if only one AI city will produce Lumber, it will share that Lumber with other AI cities.)
3) Production of Lumber has relativly high priority for AI considering Professions.
(Definitly higher than in Vanilla or TAC.)
4) Deforestation itself will produce Lumber.
(So usually AI will get most of the Lumber it needs through its Pioneers.)
--> Deforestating ist not a big issue for AI anymore.
(You will almost always have one AI city still producing Lumber.)
I had also tried to implement logic to teach AI Pioneers to do deforestation and improvment construction in better ways.
(Basically I was trying to check the improvments already built in city radius.)
Although the logic seemed to be generally working, it was quite complex and heavy on performance.
Complex logic always also has the risk of running into some exception which I might not have thought about.
--> Thuse I removed that Pioneer AI logic again (from my internal test version).
(Stability and Performance were always very important to me.)
Summary:
Don't worry.
In all my internal tests, AI had enough Lumber to construct buildings.
(Without need to hurry building production. And it will definitly not buy Lumber.)