[Feature] Prevent scripts from running until sync is done on opening browser.

[goofedup]

Motivation
I have some scripts that get data from fetch GET requests. Because some of this data is based off stored date info stored in GM_setValue when I update the scripts and move to different devices to extract other info from the fetch requests it isn't reflected and then causes issues when making a PUT request as data is missing as the script hasn't updated on the new devices. Obviously a niche issue but if there's an easy fix I'd love to see it added.

Proposed Solution
Add an option to disable scripts when opening browser until scripts have synced.

[tophf]

I don't think such an option would make sense in general. Can you use GM_addValueChangeListener?