I’ve been using the workaround for a while and it works. I would suggest considering the user success story for someone trying to use opencv/numpy with snaps though.
I think given ROS2 Colcon Plugin - Failed to load entry point, Plugin properties failed, install unexpected, and Bundling OpenCV and/or Numpy in ROS snap for Ubuntu Core This issue affects multiple users and currently the pattern is try to snap, run into issues, post on forum, find work around, see the install keyword is deprecated, update to use override build, and then leave kind of ugly work around in snapcraft.yaml indefinitely. This probably takes several hours and coming from a robotics perspective I would argue it gives the impression that if a pretty core package like numpy is not well supported it makes you wonder about the usability of snaps.
Especially Gdal-bin "Cannot open shared object file" I didn’t see this one until now, but presumably this user received no help and hasn’t been active since.