It's a single knob. They are probably combining multiple compressor/limiter features into a single knob and they may be doing multi-band compression where bass compresses differently than mid and high frequencies. It may be to much to document and explain over them just to say "Just try different settings"
There's a lot of single knob doing multiple settings going on these days. Check their TC line. Minimum number of knobs, but the knobs that are there do a lot more than yesterday's heads.
Ok, that's "plausible"....