Hi,
I've just completed a playthrough with this mod on, and it was interesting to have to put more thought into tackling biter nests and demolishers, but I think at the moment the demolishers may be too difficult. For context I was playing with the Factorio+ and Space Age Without Space overhauls (so with everything with Nauvis and I had extra weapons to use). Utility science was locked behind a resource patrolled by medium worms. The medium worm regeneration was so high that nothing worked except for 60 atomic bombs fired at once from separate rocket turrets. I think I had the Stronger Explosive research at level 3 or 4 at this point, because of the utility science block. Every other weapon I tried did not work. I tried gun turrets, tanks, cannon turrets, tesla turrets, even destroyer robots. These all did effectively nothing because of the health regen. Note that I did not have any small worms spawn on my world (unrelated to this mod, so I do not know how challenging those are).
I like the idea of more challenging demolishers that require planning to beat, but I think the regen values need to be lowered significantly. Maybe even left at default or only slightly higher. The problem is that doubling the regen makes them more than twice as hard. Combining that with HP and attack bonuses and they end up VERY strong!
I also found that the respawn time for units was maybe too quick for pentapod nests. I found that large and behemoth stompers would spawn and immediately crush me (their feet would sometimes spawn on top of the player character) when I was trying to clear nests. But on the other hand, it did make bases a fun challenge to take down.
Thanks for the fun mod!