I would like to make a suggestion to add a feature that allows players to opt-out of receiving rested XP. My idea for how it'd work would be along the lines of how players can use chat commands to change their XP rate. For example, perhaps players would be able to type ".settings disable rested" to prevent any further rested XP from accumuliating while in a city, inn, or while offline. And of course a command to enable rested XP again, for example ".settings enable rested".
If approved, personally I would super love it if this feature was also usable by Ironman characters.

What follows will be some of my thoughts for why having this feature in the game might make the game more enjoyable for some players. Feel free to stop reading here if you're not interested. Thank you.
"Why would anyone want to disable rested XP?"
Because it adds "pressure". Let me explain. Picture this. You're playing on your first character on TrueWoW. This being your first character on the server, you feel a desire to reexperience the game as close to the old, "authentic" retail experience as possible. For this reason, you're choosing to play on x1 XP rate even though you've seen there are ways to increase it.
And now you just hit level 79. Just one level to 80. You've been playing for a good few hours today already, and yesterday you played a lot as well. But you're feeling good, you're having fun. You're in the mood to get all the way to 80 today. You start killing some mobs for a quest when suddenly, "you feel normal" pops up in the chat. "Oh", you think. "I'm out of rested XP. That's unexpected."
As I'm sure many of us know, if you level slowly during the higher levels at a x1 XP rate, it becomes a rarity to ever run out of rested XP, since it accumulates at a constant, percentage based rate. You get used to being rested. Now answer me this. If you yourself were to find yourself in the situation I described above, how much more likely would you be to stop playing for the day to let rested XP build back up? Not at all? Perhaps a little? A lot more likely? The answer here will be very subjective I think. This is what I mean with "pressure". Depending on your personality, your mood, your temperament etc. Rested XP - just by being in the game - might "pressure" you to stop playing for the day, even though you originally wanted to keep playing.
And since rested XP also has a cap on how much it can accumulate, it might also "pressure" you to start playing again if you've been gone for two or three days, since you know that you wont gain any more rested XP until you use some of it up. You might feel like you don't want to "waste" or "miss out on" rested XP.
I think that for some players, being able to avoid this "pressure" would make the game a more enjoyable experience. Even if avoiding it would penalize them by reducing their levelling speed. Thank you for reading.