Nah, IS2 is fine on sight blocker maps like Elst. Keep it shit on open maps, it's perfect as it is now, alongside most heavies like Pershing and Tiger.
For the love of god, move back the hotkey to reinforce STG Obers back to F with grid keys. I had a stroke mid game when I saw it was on E just so the IR detection passive icon could be at F.
Also 221 med crate and smoke have the same hotkey.