If you have a lot of upgrades, you may have noticed that opening the upgrade tab in your inventory causes a severe slowdown of the game. That's because each upgrade counts as a unique card, and BattleForge's card sorting algorithm is terrible.
The proposal is a fix that will prevent the upgrades tab from showing "used" upgrades. In other words, when you click the upgrade tab, you will now only see the upgrades which have not been applied to cards. This will stop your game from freezing when you open the upgrade tab with many upgrades.
Understandable to make that mistake, though, since I did say I want the BF balance state to be the same upon release and then start working on balance changes so the game is on vanilla balance for a reasonable time so returning players can experience the cards and such as they were before we start to improve. I never expanded this reasoning to anything beyond card/game balance.
As for the original post's request, I see no reason why we shouldn't implement this. The upgrades a player has equipped are already conveyed through a card's upgrade lines, so in the rare case that someone would need to know whether they have an applied upgrade they could just look up the card instead. This is just a very straightforward QoL change that I'm more than fine with having implemented ASAP.