Two ways I've found to eliminate bryopsis fairly succesfully and without casualities in my nano:
1. Tech M: Turn off all your pumps. Spot apply 1/2 the daily dose noted on the bottle to the patches of bryopsis. Your MG will go up, so test offten. I didn't actually raise my MG to the levels that most people note online. I think everyone says 1800. I think I went up to 1700 or so, but I was dosing daily-ish for a few weeks. After the Bryopsis was gone I continued to do the same thing on the areas where I remembered the bryopsis was.
2. Peroxide: Turn off all your pumps. Spot apply peroxide to the areas where there is Bryopsis. You'll see the bubbles rising. I think I did between 1/4 - 1/2 ML per gallon every other day (the lowest end of everyone's recomendations). This will kill the bryopsis (and hair algae) in a few days, but I think it's less permanent than the Tech M approach.
I turn off the pumps with both of these because I think it helps target the problem as opposed to just dosing the entire tank. With the Tech M, it's more dense than salt water, so you can squirt it above the patch and watch it settle through the bryopsis. The Peroxide is difficult to see, I think it rises, so I use a syringe to inject it at the base of the bryopsis. You'll see the bubbles rising from the patches of bryopsis after a few seconds. I usually leave pumps off for 15-20 minutes (anything more and my tank temp starts dropping).
I've actually done both of these simultaneously before as well without any noticeable ill effects.