The CombiPan is a great shrunk-down dip and dunk and a lousy daylight tank. The best way to use a CombiPan is to use at least 2, better 3, tanks in a process line, moving the film from one to the next using the holder to also agitate. By placing the tanks in a waterbath good temperature controll and stabilization is possible allowing for nearly any process including E-6 with results no worse--- and generally better--- than possible with any of the rotary processing machines.
Trying, however, to use the CombiPan as a daylight inversion tank will, I think, lead to nothing but frustration and uneven negatives. Flow rates are too slow, agitation is less than ideal and sometimes they even leak--- and worse still, if the retaining clip is in any ways damaged or incorrectly installed film will fly off ruinging the entire load.
In a process line, by contrast, I think there is no better solution for doing 4 or even 6 negatives at a go.