Don't people look through a wallet software's settings when they use a wallet software or app for the first time? I would do, for certain. You would spot the denomination setting pretty quickly, won't you?
Some people do, most people will notice the unit at least.
But as expected of the mainstream users, there will be those who can get confused with the unit even though it's displayed in the balance.
If you have the time to check every thread here in Electrum boards, you'll come across issues posted by users that expected the default unit to be BTC.
Mainly those with "
fee is xxx% of the amount" topics.
It's a long time ago, I had to install Electrum on a system that has never touched Electrum before.
You can test that on an existing Electrum by removing the
"decimal_point": x, line in the "
config" file in your electrum datadir.
Electrum has to be closed before editing the file.
Without it, Electrum will set the default.