Framed Blocks mod adds a number of specially shaped blocks which can have the texture of other blocks applied to them. Most of them behave similarly to existing blocks, like slabs and stairs. I thought this opened up an opportunity with Mighty Architect for making a theme that uses them. After building the schematic, the user could just go through and texture all of these to their liking.

I ran into an issue where blocks used in pallets that are from the Framed Blocks mod do not have proper orientation (facing/axis) when used in themes. It looks like your mod has it's own method for saving orientations, doesn't get the Axis + Facing correct for these.

https://www.curseforge.com/minecraft/mc-mods/framedblocks
design.json.txt
pallet.json.txt

What I designed into the theme/pallet:

What actually prints:

The slab blocks from this mod have similar attributes to stairs (Half, facing, waterlogged, etc)

I created a mock-up of what the end result would be if this would work correctly