Problem with diverter valve on Hotpoint FDUD 43133P

Hi All,
My first post.
This dishwasher is pretty good apart from an intermittent problem with washing the lower tray.
The problem diagnosed as due to diverter valve not operating correctly. This valve was unobtainable as a spare. Purchased a used one. Checked working before fitting. Problem not solved. Engineer advised new main circuit board. This was not changed. I checked the old diverter valve and it still worked OK.
I noted that the motor in the valve was a synchronous mains motor without the mechanism to ensure it turned in one direction only. The valve requires a single rotation direction. The service engineer said that function was performed in the electronics. He didn’t sound convinced.
It would seem possible that at some point this motor may turn in the wrong direction, due to wear or age possibly. The valve would then jam. On subsequent operation the valve may continue to be jammed and so the diverter action would not be performed. At other times it may work OK. I’m guessing there is no feedback to let the processor know if the valve has worked correctly. Changing the main circuit board would not solve this problem. Changing the diverter valve may or may not solve this problem in the short term
I’m suggesting that, if there is room, the diverter valve could be removed and replaced with a second pump. The motor run signal could be used the select which pump was operating. This is obviously not in the manufacturer’s interest as it would probably cost more but would be cheaper than replacing a perfectly good main circuit board.
I’d be interested to know your opinions, please.
Doug