I’m 35 and was working with an oven in the “50+ year mark”, just a few years ago.
I have preheated overnight
I have baked cookies, cinnamon rolls, frozen pizza etc… overnight
I’ve had it justa warming my house, cause I didn’t turn it off
Maybe I’m irresponsible… maybe older ovens are less forgiving. When my stove/oven was finally replaced, I didn’t have that issue. And it also cooked properly/evenly (a bonus).
What I’m kinda saying is: old stoves/ovens don’t “easily” die, because they’re easily repaired. But ya gotta keep your eye on them when they’re cooking. And they will keep cooking, regardless of timer.
That “timer” is an analog ‘buzz-noise’, but it don’t do anything to stop the heat. It’s a reminder/warning… for you to come deal with it