I think a few Rohloff owners have shifted their brake levers around looking on the Thorn forums. I did think about trying it but you’d need to do it on every bike you owned.
For what it’s worth I don’t think your mad to want to have your main brake controlled with a different hand to your shifter. Some of the replies have just been “well I’ve managed perfectly well so far so why change anything.” It doesn’t seem like anyone’s actually tried it and found they don’t like it.