Spawning Ruins templates in the Beneath dimension (https://www.curseforge.com/minecraft/mc-mods/the-beneath) results in said ruins only spawning at the topmost possible point of the world. Attempts to mitigate this issue e.g. use of embed_into_distance property unsuccessful as they result in oddly placed ruins (floating, stuck in the middle of stone etc.), likely a result of the offset not taking into account present surfaces.

A possible solution might be starting the search for a surface to place a ruin lower than the highest possible y-value as this may prevent ruins from getting lodged in the ceiling in the first place but, that may be difficult to do and after all I'm not a dev so, yeah. Would be great if this could get a fix though. Thanks! :)

Try adding bedrock to "unacceptable_target_blocks".

Requires a completely different algorithm to find viable spawning points. I believe the old code just randomly picked a height and tried it... not a priority