Incredibly niche and may be a Mac-only rec, but I've been really wanting to use Firefox containers to minimize tracking, but something I keep coming up against is that I always use cmd+t to open a new tab, but Firefox doesn't have a way of setting a new tab to open in the same container you're currently in (and having to click multiple things to do something as simple as opening a new tab is ridiculous).
Solution: First, install the Easy Container Shortcuts Firefox extension and leave everything as is. Next, install Karabiner (it maps keys on your keyboard) and create a custom modification that maps cmd+t to cmd+opt+t (here’s the json!).