They actually do one of those already (at typically stupid Garmin prices)
https://www.amazon.co.uk/Garmin-Universal-Adapter-KOM-Cycling/dp/B076P316M8/
I did this using Otterbox stupid belt clip. Obviously it requires an Otterbox case.
https://www.lfgss.com/comments/14260056/
@Hulsroy started
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They actually do one of those already (at typically stupid Garmin prices)
https://www.amazon.co.uk/Garmin-Universal-Adapter-KOM-Cycling/dp/B076P316M8/