I did a quick look through the open and closed issues here, and did not see this discussed. My apologies if I missed something.

I am just starting to play around with DO, and when making the Fancy Door (Full), the Frame Material and Center Material on the output result feel like they are backwards

When I look at the output results, the pieces that are using the "Center Material", I would definitely call the "Frame" parts of the door, and vice versa. Compare it with the Fancy Door (Creeper), and those results are what I would expect to see.

At the end of the day it's a minor thing, it just felt backwards when I went to craft them.