[Ndymium]

I have an Ultimate Hacking Keyboard, which is split like the ErgoDox. I don't find any issue with the positioning. I personally think about keeping them in any position relative to each other, but rather how each hand/wrist feels comfortable with its own half. Currently they are both nearly parallel to the edge of the table and positioned so that my hands are straight, not angled. They have rubber feet so they don't tend to move.

[andreareina]

How easy is it to get the hand back into home position after using the mouse on the split?

[Ndymium]

I don't know as I don't use a separate mouse anymore, I use the mouse layer on the keyboard itself. My hands don't really leave home position too much. I moved backspace to the right side thumb clicker too, so I don't have to stretch for it.

[selftest]

Super easy if you have homing indicators on the keys (F and J on QWERTY layouts) like you would on other keyboards, only slightly more difficult if you don’t.