Yeah the Challenge Log was poorly designed.

When a Challenge completes it needs to pop-up & ask you which class you want to earn the reward.

It's so annoyingly easy to accidentally pop a Challenge & forfeit the experience because you were on a 50.

Whether it be by just going about your busy doing dailies/dungeons/fates...

It feels too censory/inhibiting in that sense.

"I've been FATE grinding for 20 min's... let my interrupt it by clicking over to my low-level THM so he can earn the reward on the next one!"