Mohammad,
Have you investigated changing the save name temporarily for a single save option - like for a backup, or even with a different filter to save a limited set of tiddlers?
I imagine a button would need to set the fieldname, initiate a save and reset the filename.
Alternatively if we could have a save anything as any name on a button click would be nice. For example save all changes stored in local storage to a file of username.json without the save as dialogue appearing.
Regards
Tony