I had something similar before I bought the one I referenced with this out front mount from TUSITA https://www.amazon.com/dp/B08XW624Z4/ref=cm_sw_r_apan_i_17NZDWPEENYFGJ7H7FHE?_encoding=UTF8&psc=1
I find the center support is less flexible and absorbs more shock...
For me, I wanted the phone to be in the closed position only to use it to control music and for the occasional check of maps or to make impromptu calls...
I have a Wahoo Element Bolt v2 for maps and such...
Thanks for sharing your ideas!
Use a rubber ring similar to the one included with this https://www.amazon.com/TUSITA-Compatible-Garmin-Computer-RTL510/dp/B08XW624Z4/ref=mp_s_a_1_4?keywords=garmin+handlebar+mount+bracket&qid=1646091686&sr=8-4
I’ve used old rubber bracelets for this.