I didn't get through it last night, but didn't see anything that seemed like a problem.
Originally Posted by Mr Bill
This evening, I tried a different version - how much would the carried-over stop bath concentrate in the fixer? (One could consider any contaminant in that tank to behave in a similar manner.) Result: This does not cause problems either. The unwanted stop bath contamination (in both fix baths) initially builds up fast, but by the 4th and 5th cycle (of moving fix-2 into the fix-1 position) the rate of change has almost stopped.
So I still do not see a plausible reason for the periodic dump and restart of the system. (I'm not recomending to disregard Kodak's instructions, just saying that I don't know the reason for it.)