I have rarely seen a small magnificent.
If you want to go another route, turbo snails will eat the macro once all of the easy algae is gone. I used a bunch of them in my tank to get rid of byropsis and grape. I pulled out as much as I could by hand. Then, I put in 50 turbos. Within 3 weeks, it was all gone. Then, I spread the turbos out in my other tanks. The 8 or 10 that are still in there keep it from coming back. My magnificent would not touch the byropsis.