Call it Aussie inginuity, bush mechanics or whatever.......
........but I made up a spare master cap to which I drilled a hole and fitted a standard tubeless tyre valve.
To this I set my air inflator and regulator to a small 8 psi setting and hopped under the car to work the bleeders, only stopping occasionally to check the level in the master.
It's great not having to ask the missus "Foot down, hold, foot up" two thousand times!