So basically my idea is this.
Every time you TR your character, every quest that you didn't do during that life gains a "Relic Bonus" to the amount of EXP it provides.
If you still don't do it on your next run, then the bonus is granted again, until it stacks up to some cap.
+15% each time stacking up to 150% maybe?
All stacks would be lost on completion, obviously.
This would encourage people to mix things up a little, and occasionally step out of their maximumly efficant speed run paths to play a piece of content that they haven't touched in a while.
It would also make buying new old questpacks more tempting, because they would have accumulated massive relic bonuses while you ignored them.
Thoughts?