Today was not super fruitful. Tried to figure out why some of the tiles are not rendering properly. A few things I got stuck on are:
some tile sets like 92, 28 and 7 keep being imported with a broken normal or face geometry so it appears a lot darker
there are some artifacts when the static mesh build light, if i force no precomp light, the problem of darker tile sets persists
If I force no precompute lighting the problem of the darker tile set persists
I tried referencing threads like this to figure out what changes I can do to make the situation better
increasing the lightmap resolution from 32 -> 128.
adjusted the padding of the lightmap from blender unwrap with a more generous amount 0.32
adjusted indirect light quality in ue4 to 2 and indirect lighting smoothness to 0.1 (based on this [modular lightmap thread][1])