I noticed something weird. The issue is that if you leave the itch app running for a long period (a week) the app will slowly uses more and more of CPU % (as seen through Windows 10' task manager). It's like a memory leak, but for CPU.
I noticed this because I keep itch minimized in the tray and never turn off my computer for weeks. At start, itch uses 0% of the CPU when minimized. But after a week, it climb up to 17% of the CPU, still when idle, minimized in the tray.
I noticed this because when playing idle games, it's not unusual to leave the game open and running all day for weeks. In case it's important, the game I'm currently playing is Light Game (https://narf.itch.io/light-game). I'm playing the Windows version, launched through the itch app (not the html5 version). And just to be clear, it's the itch app that uses more CPU, not the game.
I haven't tested if the issue occurs when leaving itch running for a long time but without having a game running too. If you think it's important, i would be glad to test that case for you. Or to send any logs or whatever you would like. I just want to itch app stay top quality (cause it LOVE my itch app!)