I really dislike the stock footrests on Bonnevilles [not too keen on rearsets either].
So, since I traded my Thruxton foot controls for Bonneville ones [glad I did that], I put the passenger rests in place of the chunk-style Bonnevilles. I used a large nut [3/8" profile] to get them extended to about the where stocks are. Seems good. I am going to use some 3/8" aluminum stock and mate it to the outriggers so the footrest bracket is fully against the aluminum, lower the mounting hole about an inch, dimple the aluminum for the guide pins, a dab of black paint, and go.
A benefit is the detent when the footrest is lifted up and you are on the bike moving it around, as I was in the garage. No whacking of the shins.
I am not a peg scraper, so no concerns there. They look pretty cool too: