Liimert , On his channel there is a tutorial where it only takes 20 minutes for one road. I do not think that he wants to spend his best years of life on a project that a priori can not adequately work on Sanka engine.
It's a pity, of course, that you did not remake Grove Street yourself. I have nothing against Insanity, but I would like to see exactly your vision. I think it would not be worse, or even much better.
Adapting for Insanity is good, but Biocont.ipl looks shitty with standard vegetation, and without it on the map is too empty and boring.
It is not entirely clear why it was necessary to cut an object for this purpose, when effects could be used, avoiding possible problems, and the script would be easier.
On his channel there is a tutorial where it only takes 20 minutes for one road. I do not think that he wants to spend his best years of life on a project that a priori can not adequately work on Sanka engine.