Most of the bolts on my mtb are m5 so instead of carrying a bulky multitool I designed this mount that can be screwed into an empty waterbottle cage mount hole on my bike, I made two options, one that is flat on the bottom, and one that is angled, this is just so that the mount will work on bikes with different tube shapes, i recommend printing in tpu but it should work in most filaments. I have included the onshape document below if you want to change it to your needs.
https://cad.onshape.com/documents/ad7aa067822182206fc5a385/w/a3bcd22bb2671836ac8cef2b/e/c655a3632442b8577e72acde?renderMode=0&uiState=6544341d1f49927ebc795b41
The author marked this model as their own original creation.