FWIW I had 1 pump mount that I liked very much so I bought 2 more for my other bikes. I just have to remember to move the pump to whatever bike I'm riding. the bracket I like sits under my water bottle cage on the down tube. the pump clips in but there's also a velcro strap to keep it attached to the mount.
something like
this
looks like you're not the only person to mount a pump on a fork
https://bikepacking.com/gear/crankbr...v-pump-review/
https://www.printables.com/model/195...29-mm-diameter
good luck!