Too low a flexibility allowance could raise potential pressure to release more land later, whilst too high could result in excessive growth threatening the national growth area relationship.
Gallai lwfans hyblygrwydd rhy isel arwain at bwysau posibl i ryddhau mwy o dir yn ddiweddarach, a gallai lwfans rhy uchel arwain at ormod o dwf gan beryglu'r gydberthynas â'r ardal dwf genedlaethol.