fyi...since you are so stunted...

there is a culture difference in 1) attitude 2) actual practice 3) laws
Many/the majority in the US and those in the UK differ....You may believe a
certain way..that doesn't make it law..or humane or the "right thing" or the
"only way to think". I hope cats in your charge don't get run over by cars,
die from ingesting antifreeze/coolant/other poisons, mauled/killed by wild
animals/dogs/humans.

... To have
a healthy cat, knowing you will keep it in 24/7 marks you are being
cruel, selfish, or both.