I'll bow out of the conversation on re-using DIN rail terminals - I'm not familiar with them enough to advise (Only recently realised there's such things as shorting links). If you have the rail installed (which you have) it feels like a good opportunity, but others here with more experience will offer a more accurate view.

About the DIR - probably best to be set similar - if you miss a DIR change then you might end up with a single step in the wrong direction - but as this would only be on change of direction the error is unlikely to accumulate.

I take your point though that you'll be migrating to UCCNC next week anyway... I wouldn't sweat it too much.