I haven't kept OEBT, but RCS are like roaches. They'll survive a nuclear bomb, if it doesn't have copper in it.
Seriously I had a tank I started for RCS and had to move them in quick because other fish stalking them. It went through an ammonia spike, and a huge and very long nitrite spike (>5ppm for a week or so, with water changes). I only lost a couple out of the 20 I had, and now they're right as rain. If the water quality gets bad they'll start to lose their color a bit, so watch for that. Now that my tank is settled they've all colored up nicely.
30G AquaClear50: Lightly planted, 2 glofish, 2 platies, 2 ottos, 4 kuhli loaches, a mystery snail and ghost shrimp.
10G Sponge filter: Heavily planted, 2 ottos, 2 kuhli loaches, red cherry shrimp
2.5G MiniBow Hood Filter: Planted, Betta named Sushi