It might be a stretch to think of an SF-2 as having two clean channels (signal paths).
Yes, in stereo you can have 1 filter + 1 parallel clean (direct) per channel, so yeah that’s 2 clean channels ...but feeding 2 separate outputs.
In mono you can have 2 filters + 1 parallel clean (direct) only.
The only way to get 4 signal paths is to configure it as stereo but patch the output of channel A into the input of channel B -- so it’s actually mono -- and then the two direct signal paths aren’t both “clean” since B is being filtered by A; they're in series, not parallel. And imho the real magic of an SF-2 (and these clones) comes from the parallel blending of direct + filter(s).
Signed,
/Captain Pedantic