in 1.18.2-2.0.25, rain particles visually come through thatch, though it appears they count as cover mechanically (e.g. for firepits).

Unfortunately, for now, this is intentional - vanilla uses motion blocking to detect if a block is rained on, thatch is not motion blocking, therefor it permits rain to pass through. So short of two options - either modify the way vanilla handles detecting rain (bad idea), or making thatch motion blocking (not happening), there's not much we can do.

*We were looking into alternatives and some very cheeky behavior that would allow thatch to behave a bit like dripleaf, but unsure if it was viable. So for now, working as intended.

Something just occurred to me: would it be possible to make thatch behave like leaves? Since, in TFC, leaves allow players to pass through like thatch, but (for the most part) block rain and snow.

Was actually fixed by 0c84a82