On my unit the rear switch was definitely broken (cracked). On the units you sent all switches looked ok but I had no way to test except trying in unit. I took the cleanest looking switch from your unit and put mine all back together. Worked for 1000 miles and then failed with indicated low pressure in front circuit.
One the 3 I have autopsied to date failed the same way.
Front fluid pump fails mechanically, stalls the fwd motor, motor draws too much current, shorts the windings, and consequently blows the power mosfet on the board.
If spares are available, the unit can be successfully repaired.
Motors and pumps are not available new from what I have been able to find.
Luke, I was trying to get an idea if there was a very precise "common factor" in the failures and it appears that there isn't! It would appear that the failures are just "random"
I think in most cases, that frequent use of the bike / both levers and strict adherence to the fluid change regime is the only way that it will "survive" for any length of time. In fact I am just doing all the circuits every year in an effort to stave off the inevitable!