Loving the mod! I'm getting close to building a matter conversion block in my base. Exciting times.
I'm running v18.9 and have been experiencing an issue that makes it very difficult to outpost. Even after clearing the creep and eliminating all biters in a large area, I'm getting an issue where placement fails with a message "Construction blocked by enemy". It will usually spawn a biter too. If a construction bot tries to place an object, it just drops the item on the ground. Sometimes it goes away after a while and I can finally build.

Here are the mods I'm running. I only loaded those you recommend on the mod page.
Fluid Must Flow
FNEI
Vehicle Snap
RSO (With vanilla biter generation)
Armoured Biters
AAI Zones
AAI Vehicles

Thanks!