I've not dosed PO4 for a week now with no ill effects on any of the plants. I've increased KNO3 a little. My caulerpa prolifera gets transparent tips if I don't keep up. I may actually be dosing less traces than you even though my tank is bigger, at 75g, with a fairly large plant mass. What I'm using is the Kent macro trace mix which is like water compared to TMG.

At the moment, unless I can nail down a definite PO4 defficiency, I'm not going to bother with it for now. PO4 is an enigma for me. It's needed, but not too much not too little.