I am also contemplating replacing my CQR with a Delta for use in Greece, due to repeated difficulties when weed about, at all other times the CQR has been OK.
I have an 18Kg Delta for my Bav 36 though not fitted yet. I tried it dry in the yard and the bow roller appears to be OK, but when docked in the cradle the locking pin over the shank will no longer fit as the shank is much wider on the Delta, so some modification will be needed.