Good day.
I’ve never rakedd or graded a driveway like what you described with a BX, so I may be of low or no help.
For wanted to rake or pull the material uphill, do you have a traction issue pulling your plane up the hill? I’d think about that first.
then if had nothing how would you do manually…would you take with a garden rake up the hill or scoop with a shovel to bucket and carry up hill and then take back down?
to me a Harley is awesome…ve watch them in use online and in person and they are awesome at one thing. However they leave spoils to be cleaned up as a second pass or after the pass. I’ve only seen them used on flat ground…I’d rent one vs buying first to make sure it would for your purpose.
if you think you have the traction to pull a box blade it should bring some up the hill, but how much do you have? To get into the box (lots of trips or just a few?)
is a significant amount that maybe you want to scooop with loader and bring up hill to rake or grade back down?
I recently bought a rake and what I would wonder is how much gravel could I take up a grade…I’d probably scoop it and transfer to top and grade back down. I don’t know that is correct but I would try that first.
I would also offer that a hydraulic top link and tilt function would be helpful with a rake. So is a wheel kit…all three if you think you will need to trim the implement a lot.
IMO it sort of depends on the process or processes you want to have and direction of travel for the work.…I am not certain there is a perfect tool for what you described.
is there a reason you can’t scoop the t take it uphill and grade it downhill? (I’ve not used a plane before so I am asking)
just my couple thoughts. (As I stated might be low or no help

).