Turn On/Off Rested EXP Usage

I think it would be fantastic if there was a toggle switch to turn rested EXP usage on and off.

Sometimes, people want to level a new class, but let's face it, you aren't getting much bang for your buck if you switch to that Lv3 and sap your rested EXP in five minutes, compared to playing your Lv58 and having it last for a few dungeons.

As another example, I like to level every class. My girlfriend doesn't want to level everything. When possible, we static together, one of us playing a healer/tank while the other plays a DPS for better queue times.

Since I'm leveling more classes, I have to do a lot of solo leveling. When I'm on my own, I'd like to be able to turn off the rested EXP so that when she and I are playing together again we remain in the same EXP range, instead of my rested EXP disappearing long before hers does, causing her to end up way ahead of me.

Seems like it would be a simple thing, and I imagine there are plenty of people who would appreciate it.