Is your friends list still full of your RealID friends' alts? Could you use some of that space in your friends list back?
This addon keeps an eye on your Real ID and normal friends lists, and any times it detects an overlap, it will prompt you to remove that character from your friends list, since you can see them online via RealID already. It keeps track of the toons each RealID friend plays on internally, and will check the friends list on each of your characters. This data can be cleared with the slash command /ric clear. Friendship removals can be undone one-at-a-time with /ric undo or all removals can be undone with /ric undoall.
The popup window to remove a friend will give you options of "Yes", "No", and "Ignore". Clicking Ignore will add that character to an account-wide ignore list, and you will not be prompted to remove that character as a friend in the future. The list of ignored characters can be cleared with /ric clearignored.
This addon is written to use as little memory/CPU as possible, and will disable itself almost entirely during combat. If you also have AddonLoader installed, it will be LoadOnDemand. Automatic prompting to remove friends list entries can be disabled (/ric auto) and then accessed manually via a slash-command. (/ric scan)
For a brief list of available slash commands in-game, just type /ric by itself.
If you encounter a bug, unexpected behavior, etc. please report it on my GitHub Issues tracker. I will be checking this page and its sister at Curse/CurseForge infrequently at best.
Because all relevant info is already stored internally, detect when Battle.net is down/goes down, and add those characters back as regular friends temporarily. Clear these temporary friends when Battle.net comes back online.
An extra-privacy-conscious mode that doesn't record any information about your Real ID friends' alts. It will only match a character they are currently signed into, and will not save any information between sessions.