Just remember, the tourer has the rear guard as part of the bag mount system. If you laid or tipped the bike over, it came to rest on the forward and rear guards (and protected the bags). If you do this with a standard, the bags very well may hit, maybe not hard, depending on how hard it goes over.
I always wondered why no one ever came up with a rear guard for standards with hardbags (short of the entire tourer/interstate mount system). Champion made one years ago, but they are nearly impossible to find.
The little guards that Tsukayu sells bolt right to the bags, and could easily rip the bolts out of the bags, or crack them in a fall. Might protect the paint in a gentle tipover. Would need mounted with wide rubber & plastic washers, inside and out.
Champion valk guard.

A home built guard need not come up to the top of the bag, just need a heavy duty steel U loop down low, similar to the guard on tourer/interstate. How/where to mount would also be tricky.
Like this. (maybe a longer loop for the Jumbos.

My buddy with the brand new CVO road king just discovered the bags that come on the bike are extra large (lower), and the (standard) rear guards that come on the bike do
not hit before the bags do in a tipover. Nice work there boys.... and only $30K or so.
