Looks like gha to me. I've had a little outbreak of what looks similar (to me from the photos). Picked up some big turbos and they're (slowly) removing it at a faster pace than it can grow. I have 4 big ones fwiw. Idk how much algae I had compared to yours either so mileage may vary if you're on the same road. Might also pinch out as much as possible during a wc. Good luck!
GFO, Phosphate Rx, (my fav) PhosGaurd, test, change out weekly. A bunch of hungry Turbos. A bunch meaning 20-40 once the problem looks to be turning around, take some of the snails back to lfs for credit. 4-8 weeks you should see a difference.
I can't tell from the pictures if it is bryopsis but... Bryopsis can start out looking vaguely like tufts of fluffy grass but soon it grows longer, branching and fern-like. If it's growing more like grass and staying that way, then it's probably not bryopsis.