To get back on topic....

I do not use work offsets very often, which I presume depends on the accuracy of determining machine zero by homing all axes (axises ?). Most of what I do is one-offs and for that I zeroise locally when the piece is bolted down. If I have to do two or more, then I use a simple jig and, as I said before, leave the machine in a known position if I have to switch off and return to it next day.

It would be interesting to determine the increased accuracy with a dual sensor set. I would guess that it would not be significant for most home built machines.

What do the big boys, like HAAS, do?