Currently, level freezing gain a large amount of advanced refine runes. Deliberately holding back your character level to increase rewards is fundamentally against the way the game is designed to be played.

A pretty simple solution would be to simply give 1 advanced refine rune for each daily mission completed for players level 80+. It would still take 3 weeks from those adv refines to get a single item from lvl7 to 8; or 2 months from level 8 to 9. So it would not unbalance power or anything. This would completely defeat the whole point of level freezing for sage.

This is what happens when I froze my f2p char in UK servers... Nothing is fair about 1 shotting a bunch of poor low levels on round 1.