It was somewhere outside Barstow when wrote:

You don't want to replce it with a faster filling one if the new one
would fill faster than the overflow could cope with

Depends on why it's "faster filling". A Torbek fills faster because
it fills at full rate until it's full, then closes. A traditional
valve gradually throttles once the tank is about half full. This
doesn't mean that a Torbek will overwhelm a properly sized overflow
though.