The engine should be rebuilt from the ground up though. It’s full of problems and it’s fundamentally dated, for example one of the most obvious things a new version of the engine should include is making the world completely seamless - no more loading instances, no more loading screens entering interiors, etc etc. But all the other problems with the engine need addressing. And they can do a huge amount to make it better for the mod scene if they rebuild.
Continually slapping more and more fixes on this engine fundamentally ignores the fact it is impossible for it to get around several issues it has at its core without a rewrite.