Right now, it seems like to reposition cards by some field F, you have to change the Sort Field for the model to F via the “Fields…” tool, then use “Reposition New Cards…” to reposition, and then revert back to the original Sort Field. What if the “Reposition New Cards…” dialog contained a combo box where you could select which field you wanted to reposition by?
If accepted, I may be able to help with the coding of this feature (indeed I was working on my own repositioning add-on when I realised that what I wanted to do was possible by changing the Sort Field temporarily.)