IMO only way to do that is to run a channel on the ceiling to get the electrical where you want it or if you can just get an electrician to move the box the only issue with that is the ceiling might then be needing to be painted for sure

Definitely possible. We just had an antique fixture altered from downrod to a chain so we could swag it in my daughter's room. But we paid a local lighting store that does custom alterations. I wouldn't want to try this myself unless the fixture is cheap enough to throw away if things go wron.