I don't think I'm at risk of breaking strings.. The nylon-strung banjo is a low tension instrument with rather floppy strings. The historical gauges were 10lb, 15lb, and 20lb line, but the line was the harder wirey nylon. It was all monofilament- not copolymer.
Stren feels and sounds pretty good, and the tension is the same as the Trilene I tried. I was surprised by that, since I thought Stren would be lower tension. Maybe a lot of the properties of the nylon that are relevant to fishing go out the window when its strung up to pitch on a musical instrument?
By the way, I use Trilene Big Game when I fish, but it made for terrible instrument strings. It doesn't intonate well. I'm surprised Stren has good intonation since it certainly doesn't feel like it has a consistent diameter.