I own an 11 inch M4 iPad an bought an ESR folio case with its separated magnetic case. After a few months I acquired an ESR keyboard case and to my surprise the magnetic cases are not compatible, honestly a massive design screw up from them.This is a simple solution, I printed some edges to glue to the original folio case and now you can just switch them up on the go in a functional enough way. Probably too niche of a problem just uploading in case someone is in the same position I am.