Ejection port (kinda) ?
And trigger area.
This is a pet peeve of mine. I don’t like anything blocking either of those areas. If it folds and impedes access (or ejection or other action required for operation) in the folded position, I’m solidly against.
Considering the point of folding the brace is to make it more compact; if I’ve got to unfold the brace for operation, then it kind of defeats the purpose of such a small package.
But then again, with .45ACP, there’s always the 1911 in a more compact package. Double-stack even.