Once you find the fuse that passes the highest current, why not just place a switch button in series with it? Turn it off when exiting the car. Add an LED to show when it is on.
It was not all that easy to get to and not all that easy to mount a switch securely near by. May be I just lacked imagination.
The real reason and the part I skipped was the leakage current was getting worse over time. By the time I replaced the MICU it was close to 2A draw. It was just a matter of time before it died.
Personally, I'd go for a relay on a non-problematic circuit.
But I also get why you might just leave it disconnected - if it's pulling a few more amps with no clear cause, what is going to go wrong with it next, and what vital system will it take with it?
Oh a relay that goes on after you turned the key would be very handy. It is rather easy to find a point where there's only a voltage present after/while starting.
Of course, when the array controlled circuit would be vital for entering or starting, this would not be an option.
