Chasing fish always stresses them out and they learn to be afraid...very afraid...whenever you're then doing work in the tank. The less space they have to manoeuvre, the less chasing is necessary...especially if the size of the net corresponds to the restricted space that they're in.
They're doing great, thanks. I now have a plethora of Red Cherry, a myriad of Blue Velvet, a troupe of clear (probably Ghost) and even a few new Yellow Fire. I keep finding them amongst my Salvinia roots, when I'm removing excess.