I don't even turn on the Garmin 430/530's in the aircraft I fly! 20 year old stopwatch works far better
Sure you don't. Just like I don't.
One tiny warning: if you just pitch up and call an ATC unit in Class D, not having spoken to them beforehand, they may decline to accept you for an ILS approach.
If you are in genuine need, of course, you'll have no problem.