For those crypt outposts, have a portal and a chest OR a workbench(dismantle it after you finish the other two), not all three at once. I had a raid on top of a crypt once. Good thing I had already put stake walls around the top. There are free chests inside the crypt that are handy for storage if you just want to do portal and workbench.

Also, workbenches can go on platforms up a tree to keep them out of reach of everything but archers. Campfires don't stay lit very well in the swamp, but they don't have to to suppress spawns. There were a couple blobs that always spawned next to one of my pathways. I raised a little bit of ground, put a campfire on top, and those two never came back.

Bring a stagbreaker with you inside the crypt.