It's not sponsorblock quality, but I have trained a model for podcasts. Turns out, at least for podcasts, you can get away with a surprisingly small model, small enough it can run on device directly.

No idea if it's good enough for all podcasts that are out there. It works for me and the podcasts I listen to, and I have tried testing it against a larger corpus, but I'm one developer and I just wanted to solve a problem for me.

https://github.com/Q726kbXuN/podcast-ad-tagger