I had been working on the issue #9879 and it has raised an opportunity for a new feature in Joplin. Basically there are a lot of cases that a popup would resolve various bugs and improve client experience.
In my experience working on Joplin, there are many screens, such as the import and export screen that would benefit by being just a popup loading the process.
Other successfull or failure actions could also benefit from the use of popups.
There are also studies that show that the popups have increased client experience, and also client usability (for example, not having to wait for the finish of the import process).
The main purpose is to give the client the ability to continue using the app while the background processes are happening, and also give them instant feedback on the various functionalities that Joplin already have.
I am looking for your opinion on this feature, to start working on it as soon as possible.