Agreed, when I update room builder in unity it takes it 30 minutes to process the file.
Also, having it split into different files will mean that there's no need to reorder stuff around when new type of things or new row of things gets added, so it's more future proof. I already had to redraw my walls when new wall types got added and shadows moved.
And if someone really wants whey can make single palette for room builder things... in Unity they can anyway.
As a side note: would be great to not move the tiles around in the tilesheet if possible, it makes updating them easier :D