Huh. I've never got pinched for ban-evasion before despite very regularly using alts to comment in subs where I had previously been banned. I don't honor perma-bans on principle because I think they're ridiculous, but I do self-impose a 30-day ban to let things cool down a bit and avoid attracting suspicion.
Not sure what my secret sauce was, but it was never an issue for me over the 15 or so years I used Reddit.
That said, I'd take this as an opportunity to just stop using Reddit altogether.