I can’t comment on the curl, post printing, but I can say that there is a little more natural curl to the Platine sheets with the cotton rag substrate, as opposed to the RC papers. The humidity in your area may also be a factor.
As to the marks at the end of the sheet, you can control that in a couple of ways. Increase the platen gap. And, gently “turn down” the corners on the “exit” end of the sheet. Don’t bend them but you can gently flex them anti-curl-wise enough to avoid the strikes at the end.
Rand