[ajb]

Have cats with a tabcat each. The safety collar comes off a couple of times a year, once or twice it's been inaccessible - neighbour won't let you in and cant find it themselves, on a roof, etc.

For those worried about collars, I can confirm that https://www.coolcatcollars.co.uk collars do come off. You can also use a luggage scale to measure the force it takes to release.