If you can judge exposure a bit by guesstimation, trust the camera to do its work, you don't have to switch the OM 2 on, and then there is no risk of forgetting to switch it off.
The metering system will be switched on jump into action the moment you release the shutter, so if you can judge the situation, know beforehand that in a given situation, at a given aperture the shutter speed will be in a 'usable' range, you can do without the viewfinder meter that requires use of the on-off switch.
Don't know about the OM 4T specifically (i forgot...) but do know that i took the batteries out of OM 4 cameras at the end of every day using them. If i did not, they would be flat the next time i needed the camera (even if that would be the next day). Despite putting the shutter speed ring to blue B.