I keep dragon's breath and gracilaria in my fuge, and put a bit in an algae clip a couple times a week. My Scopas and Powder Brown love it. I kept it in a 'tangless' tank for awhile before it ended up in my fuge. It grows relatively slow, but is pretty.
IMO all red macros grow slowly in comparison to heavy nitrate burners.
I received some dragons breath from clay a few weeks back and I have 2 starters of other similar red macros I think dragons breath and red flame , also red palm macro and it grows stupidly Slow.
I think that's the key to them not growing out of control.