It's varies by beardie, as long as they are still putting on size they need protein, once they slow down on growth and start filling out you can slow down on protein.
Once your dragon is over 8 months old, go down to two feedings per day and allow them to continue to eat as many as they like. Your dragon may continue growing all the way up until the 18-month mark and as such, should still have a pretty protein-heavy diet.
However, with this being said, it wouldn’t hurt to slowly wean back on some of the protein in place of more greens once your dragon is around 14 months or so. This can help ease them into their adult diet.