Default tags would make finding such notes easy.
Also setting a default notebook would keep notes from becoming scattered, as they do now through being created in the most recently used notebook.
Which can accidentally be a shared notebook in Joplin Cloud.
One way to create new notes on Apple’s mobile platforms is to use the Share Sheet. A user can use the Share Sheet to share with any app that supports the flow. I find it a quick way to share URLs and images to Joplin. Optional defaults would improve the experience for notes created this way.
The closest previously suggested feature I’ve found is this, related to clipping: