I know I'm hardly the first (or last one) that will complete a Challenge on my Level 60 and see a "500 Gil" reward appear on my screen, knowing a significant chunk of EXP has been lost to the aether.

Before, when I was leveling, it was awesome to complete a Dungeon, FATE, Levequest, etc. and get this huge chunk of EXP towards my next Level.

My suggestion is a simple one, but would do wonders to make the Challenge Log a better tool and less of a bummer:

Allow us to choose when to "Cash In" completed Challenges instead of clearing them automagically.

Located at the top of the Challenge Log, labelled "Completed," show a list of all "Completed" Challenges for that week, each with a gold "Cash In" button.

There - that's it. Do that and the Challenge Log goes from being a passive, (sometimes frustrating) reward system to an actual tool that we can use to push our characters further.

Thanks for your time!