Anyone replaced secondary cats with res?

[bmwm3fanatic]

Wondering if anyone has replaced secondary cats (on oem X pipe) with resonators? If so - which resonators did you get?

Current setup is Valvetronic x oem Xpipe with resonators deleted x test pipes. Putting the oem resonators back on, however there’s still a decent amount of rasp with oem x pipe + test pipes paired to Valvetronic. I’ve heard of resonated test pipes - but I believe they are NLA. Seems relatively easy to remove secondary cats and throw on resonators in place.