"new identity" leaks memory in eventSuppressor.suppressEventHandling()
According to skruffy, each tab that's open when you click 'new identity' contributes to more lost memory.
For normal tabs, when you close them, eventually the memory from them garbage collects or otherwise returns to the system. For tabs closed by new identity, it remains lost.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information