-
They actually do one of those already (at typically stupid Garmin prices)
https://www.amazon.co.uk/Garmin-Universal-Adapter-KOM-Cycling/dp/B076P316M8/
-
Much cheaper versions:
https://www.amazon.co.uk/Beautyrain-Computer-Adapter-Bracket-Mountain/dp/B077SCY2WShttps://www.amazon.co.uk/WUYASTA-Adapter-Holder-Computer-Bracket/dp/B07DBXNWNM
But remember, you're hanging up to £500 worth of mobile phone off the handlebars with these things so sometimes ££ ain't everything...
This IS a solid recommendation. Thank you! And everyone else!