4 Wheel disc, soft pedal

Realize there is a very small amount of retraction that is normal/designed in, & is what keeps the pads close without dragging. I've used blocks to do various things, but the wood will make it difficult to judge due to it's compressibilty......on car & rotor is best......
As long as You're not crushing the hoses, pinching good/fresh ones just enough won't hurt 'em, it's done all the time. Have You tried isolating the fronts? If the pedal responds the same either way, that master may need upsized as other's have suggested, good luck!