I think I understand now. Reading through https://wiki.openstreetmap.org/wiki/Photo_linking
It’s been encouraged to use just the image key, rather than the url as the value for mapillary in osm. The image key should never change, and presumably is requested via an API rather than through the website, making it easier to integrate.
The url can be put under the image key
as an example:
Years ago, OSM would ask you to add a source=* key for an item, but when they added changesets, they ask that source attribution is added there. So as you finish a changeset in OSM, use the source tag, and include streetlevel imagery and also mapillary.
https://www.openstreetmap.org/changeset/62778421 as an example of how i’ve done this in the past.
Using overpass to locate defibrillators and then adding the mapillary image is fine. You should attribute the source as mapillary and streetlevel imagery in your changeset as that is what you are using to refine the data.
If you’re still unsure, I think the talk-be osm mailing list is a good place to get feedback. https://lists.openstreetmap.org/pipermail/talk-be/
But in my opinion, you’re not doing an automated edit, you are verifying the data before adding to osm and doing the other changes. So i do not see any problem.