I’d say make the Heartjlings detect what surface is near them, so the AI will say something like…
“if a object is touching the detection ray, shrink polygon accordingly, if object is a building, add 50% length to that ray’s shortened length with no additional collision past the object, *added length does not get longer than the max distance”
If this is possible, that will make the hearthlings feel more comfortable in a building compared to a cave of the same size