There are a lot of things I'd like for runes. But an easy qol update is to add enchanting gems to runes... Or call em fusing gems or something. Basically like the gems you can get for enchanting but for fusing. So as you slowly creating hundreds of runes, you just hit recycle or something and instead of losing it amongst your 500 other runes, it just becomes a gem you can fuse with later.
There are other qol issues that would be nice.... a sort for example or allowed to hold up to 1000. An export feature so you can see all your runes on a spreadsheet or something
An option to reroll a stat or a primary or a type. There's always been epic hail runes that just get fused because they are hail.
A rebalance of hail and blood especially. Accuracy, dodge are others that spring to mind that need a rebalance.... Or straight removal from runes.