Yep, swap that T-nut for a velcro strap and they'd never know ;-).
I'll be interested to hear how you get on back there. What sort of load do you envisage running? I've had mixed results in the EQC (15A fuse) trying to run my car fridge. When I've characterised it some more, I'll start a new topic about the EQC boot power outlet rather than pollute your EQS thread with EQC noise, but be on the lookout for voltage drops - notably when the DC/DC isn't charging the 12V battery.