Instead of having the game say "Fawns can cast temporary magic, or temporarily have skins; while Stags can retain and cast permanent magic (except on fawns)" Have the game add a timer to each account.

For as long as the account is registered, there will be a timer counting down each day until it hits a month, allowing players that stay fawns past the first Fawn-only month to cast and keep spells permanently. This would also allow fawn players to customize their fawn besides the base flowers and temporary skins that are available (devout and the red Crying Idol skin.)

I just think it would be a cool idea, and even if it never got implemented, The Endless Forest still is a great game!