I got killed in HC and lost 3 lvl 100 gems. Now to replace those I need to run (minimum) 60 grifts, plus enough rifts for keys. At 3 mins each that’s 3 hours, and it would be more, plus a load of rifts.
We could have a system of upgrade credits, where lower level gems could have more upgrade chances, so instead of 5 upgrades to level 90 gems it could be 15 upgrades to level 30 gems, or something like that.