Something like the sideberry extension integrated into Firefox would be awesome. They are able to take snapshots of the tabs and tab groups at any interval (5mins, daily, weekly etc) and easily restore specific tabs or an entire window with the click...
You can already map ctrl+t to the current group by setting browser.tabs.insertAfterCurrent to true in about:config. This changes the behavior for all ways of creating new tabs, it would be nice to have two keybinds one for staying in the group and on...
I recently discovered that you can make all new tabs appear after the current tab using the about:config browser.tabs.insertAfterCurrent set to true. Then, every new tab using CTRL+T will appear after the current tab and stay inside the group
