If you have Rotate features built into your prototypes (or even in single pieces) then that feature is also available in the palettes; just apply the facing (via right-click or key command) before dragging the piece onto the map.
I don’t believe there is a way to set the rotation ahead of time or even to set a default; how is the module to know which facing you’ll want in any situation? OTOH, I have toyed with rotation with a piece inside the pallet or tabset display and returned to find it still rotated (or flipped, or otherwise changed from default). Perhaps you can do this as you create the pieces in the module. Unsure if the rotation will be saved with the module for distribution…
You can edit pieces to rotate to vertexes by increasing the number of rotations to 12 from the default 6. It’s in the Properties