I ran into a new Canyon stem designed for gravel. It has a hole in the front plate for a bike computer mount.
https://www.canyon.com/en-fi/gear/bike-parts/contact-points/handlebars-and-stems/canyon-st0035-rennrad-and-gravel-vorbau/9102034.html
Also the old V13 mount is on a decent sale.
Europeanen shop btw.
by Nixxewend