Latin alphabet is technically canon, known as High Galactic, (the in-universe reason why the ships are called X-Wing, Y-Wing etc.) but yeah it would break the suspension of disbelief. There’s a reason after all why Lucas removed the Latin writing in the OT.

I think Aurebesh script should be there but only a simple phrase like “Skywalker Lives”, but symbols and pictures should be the meat of the graffiti art. The Aurebesh would be there as a treat for the lore nerds to decipher later, which happens frequently in SW media.