Cant find a good pic right now, but I made brackets for mounting my flags on just about anything a ratchet strap will go around, AND will fit in the stake bracket mounts of my truck bed if there is no tree or pole around.
Used a 2x3 board 12" long and tapered the ends at 45 degrees.
Screw on a wall mount flag bracket, and use a strap to secure to whatever.
I mostly will put both flags (American and POW) on the same tree offset between 90 to 180 degrees.
I will admit it can be a PITA sometimes
2015 Shamrock 21DK
2005 Silverado Ext cab
Nights camped 2017..... not enough