+2 mins? I know the GPS altitude often reads higher than what I tell ATC in a climb or descent but that’s because the timeline track containing the GPS subtitles is not precisely aligned; also GPS reads higher than altimeter in ISA+ conditions.
I can disable the GPWS but don’t want to; one day I will forget to turn it back on 
Proper GPWS disable would be/is only a TEMPORARY one, not a permanent ON/OFF option.
When you are VMC at low level on approach, in between /bound towards/ terrain, the bitchin’ betty does not offer much help but rather adds distractions to an already busy environment in an intrusive way.
Regarding watch time I compared your (verbally) mentioned time with the one the tower reported (which coincided with the GPS one in the subtitles).
Ah OK… I log time in 5 minute increments
My GPWS is a handheld Garmin 496. For sure an installed GPWS, like the $30k King box, would be wired into a non-switchable intercom input.
