With an aftermarket Pinion I'd probably ditch my Rohloff/HSD and get a hub motor instead.
That way I'd keep the hub gears with the motor.
If needed you could then use something like an 11-34 back cassette to fine tune the range of gears wanted.
Increasingly bizarre designs?
I will see your design with an HSD, Rohloff and mid drive motor?
I've thought about doing something like that but it's not simple.
As I've already pulled the back boom out ~6" to fit the hardshell seat in it's most reclined position, I probably cannot safely pull it any further out.
So I don't think I've got enough room behind the seat to fit a motor.