I personally will use Bookmarklets rather than Userscripts to fulfill the same purpose. Bookmarklets work even in locked-down browsers including Edge (bookmarks bar, not favorites sidebar).

The one I use most often is modelled after a similar one - after you fill out a web form you can capture your entries and restore them with a single click:

https://github.com/mossrich/Bookmarklets/blob/master/Bookmar...