What do you mean exactly by "the ability to install extensions" ?
That's a very global description which could mean anything - what kind of extensions were you thinking about and how would this be implemented?
I have also read your older message (commented at preview 1b) requesting a lot of Blender functions to be available within Asset Forge. You've requested features like 'knife/bisect/extrude/smoothing' - now i'm only guessing this is what you're trying to achieve if it would be possible to create (third-party) extensions. However i don't think this will be added anytime soon, i'd suggest you keep using Blender for those actions. I'm also using Blender myself in addition to Asset Forge. Like earlier said by Kenney: "Asset Forge is a tool for kitbashing pre-made blocks" and not intended for editing/sculpting existing models.
Did you have any ideas/suggestions for extensions that are not features of Blender but are related to Asset Forge; Creating a new model made of pre-existing blocks. If so, could you explain further than just "option to have extensions" ?
Personally i don't think it will be added, at least not for the foreseeable future. Honestly there is nothing wrong with using Blender next to Asset Forge for optimizing some blocks.