Well I managed to get the power supply wired up and it does what it says on the tin... no noise, no fuss, just 500w of power....

The variable output is, well, variable... and it doesn't get switched off...it sits at 42v when the 'inhibit' line below 5v or above 11v, although the SysOut line does switch off when out of regulation.

Also needs no load resistor.... works happily with no significant load.

Will continue to investigate....