It appears that the new enemies option is incompatible with Krastorio 2's more realistic weapons setting, as it leads to worm and spitter projectiles blocking bullets, making them nearly immortal when within their attack range. (It may also be due to combat overhaul, I haven't tested without)

Additionally, Shall Alien Loot does not drop anything from the new enemies.

Believe that it is possible to add compatibility with Shall Alien Loot - similar compatibility appeared recently in Rampant 2.0. No updates are expected this week, but I will add them later.

Regarding the collision of bullets- I can't promise anything. If the author has decided that any objects are an obstacle, then the projectile settings in Rampant Fixed will not help. I'll run tests with the collision area - maybe something will work out. Before the tests, I would like to clarify which faction is so successful in intercepting projectiles

Nevertheless, I played with krastorio - usually the fight took place at a long distance and the oncoming fire was minimal. At close range, area damage was used - otherwise it invariably ended in death.

I am uncertain exactly which faction, I simply enabled the mod and went to attack a new enemy nest, then noticed my bullets being stopped by spiters and worms, I know it was at least two different factions as one set me on fire it looked like, while the other seemed more like default with acid?

While writing this message I just did another test. Using default enemies with combat overhaul + K2 realistic weapons, I am able to shoot through the worm projectiles just fine, so it is related to the new enemies rather than the combo of those two mods.

I have some ideas. I think there will be a new version next week

Apologies on the incorrect information, it appears even without the new enemies, bullets collide with spitter/worm projectiles, it just wasn't as noticeable until after further testing, so that one I suppose isn't your bug after all, sorry for reporting it here.

However, I have already checked )

Unfortunately, the author of the mod completely replaces the collision models of all worms and spitters if they have a "projectile" as an attack. Standard worms have a "stream" attack (like a flamethrower), therefore they are not affected.
Also, he added a setting that allows you to disable such a replacement ("worm-spit-blockable" and "spitter-spit-blockable"), but did not bring it to the startup settings.
Nothing can be done on my part

Perhaps this information will be useful