Twenty 20 cricket rules change during an innings ( power play, fielding restrictions)
Rugby Union rules change , depending on where you are on a pitch ( avoiding a tackle, 50 / 22's for example), or depending on which players are on the pitch ( uncontested scrums)
Curling allows players to deliberately not score on an end ( blanking the end)
People accept it, as long as it is in the rules.
Have the KO Cup rules changed since the competition started this season, or are they in accordance with the published rules? I don't know because I haven't looked