This is in response to Crunchyroll's policy where each open tab with Crunchyroll's video player counts towards a stream limit, regardless of whether that tab is currently playing the video or not. Crunchyroll's suggestion to this problem was to close those tabs once done watching, but I use my tabs in a semi-bookmark fashion so don't want to do that.
My current solution to this is to close and reopen entire Firefox because it's the only way I know to close the tabs AND keep them in the tab bar at the same time. But it's still possible to forget to make some non-relevant tab active before doing this.
A related annoyance is the behavior where closing a tab automatically loads the next tab on the right. Combined with Crunchyroll's behavior, that loaded tab could be a tab of an anime that I wasn't planning to watch next, which forces me to do the above procedure to get out of Crunchyroll's stream limit again.
tl;dr wishlist
1. A function that flushes current tab contents but keeps the address and the tab in the tab bar.
2. An option to guarantee that closing a tab doesn't load an adjacent tab or make it active. If browser design doesn't allow for no active tab, open a empty tab instead?