I haven't used one, but if I wanted something really "mini", I would probably try a Lezyne Pocket Drive Pro (5.56"), and see how useable it was. I'd be making that choice based on personal experience with their Road Drive, and hoping that the build quality would be similar.

I would be curious to know how "easy" - force required, not number of strokes - it is to get to 90 psi with one of those. It depends on what compromise they settled on for the piston diameter.