Don't instance custom shape bone objects when appending armature objects

Background: Did you know that you can have an armature with a lot of custom shapes bones, without those custom shape objects being in your scene at all, not even in collections? You can delete them from your scene, and they can live inside the blendfile as unlinked (or uninstanced) object datablocks that you can only access through the Outliner, under Blender File. This is useful if you have final rigs, and you don't want to bother your rig's users with extra clutter in their scene's 3D view or scene's outliner.

Problem: When you append an armature, armature object, or collection containing an armature object, if that rig has a lot of custom shapes, all the custom shape objects get instanced to the scene when appended, cluttering the scene.

Proposal: There should be an option in the Append file browser sidebar to disable that behavior. It would append the object datablocks of the custom shape objects too, of course (they are being referenced by each bone after all), but just to the blendfile, without instancing them to the scene

The current workaround is to rely on instancing collections, nested or not, that include a hidden collection with all the instanced custom shape objects, but with the collection hidden, thus no clutter. Then you can delete them if you want

* Disclaimer: If you don't know Blender's data structure pretty well, you might missinterpret this proposal with things I didn't mean. Also, I realize this issue is a small thing really, a papercut of sorts.*