Absolutely no reason why not if it sounds OK and if your fingers can fit into the remaining space.

I do "Gairdner Child" in DADGAD with capo at 9th fret - the guitar sounds better at root, but the top note of D is then in the wrong bit of range for my voice - so at the 9th fret it is a B and the overall voice tone better.

I do "Step it out Mary" in standard tuning at the 8th to put it in Cminor