The Natural Philosopher wrote:

a 45A cooker switch wont necessarily take all the cooker elements on and
heating up, for 6 hours...every day.

Even if fitted in a commercial kitchen? Yes I suspect such kitchens
would typically have 3ph ovens and would have more chunky isolators, but
where does a 45A isolator say "not for continuous use"?

Surprisingly BSEN 60669-1:2000 doesn't appear to have anything to say on
that.