I'm going to be using new suitcases for our upcoming holiday, they were provided by our holiday insurance from our last holiday pre covid as ours were damaged. Anyway, our old cases just had holes in the zip slider to attach a padlock, simple.
These cases have a built in combination lock and a TSA lock for the airport security to use. The combination lock number can be reset using a paper clip, what's the point of that? It'll stop the zip coming open but it's not secure.
I can't see how you would attach an additional padlock unless you don't use the combination lock at all and then the zip slider and padlock stick out and would be easily damaged.
I'm not convinced my cases really need to be locked? They will be left in the hotel luggage room on our last day but we'll keep passports, valuables etc. with us and they'll be in our carry on luggage for the flight.