As title really. Have you reused them and not died yet?

I always reuse my 10sp links. Never had a problem.

I’ve reused both Shimano and SRAM quicklinks without issue, however I have also seen the captive pins loosen and fall out.. presumably from repeated reuse. So, yes.. to a point.

I’ve also broken and joined Shimano chains without using the snap off pin. I’ve been doing this for many years as I had no idea till recently that thats not the way to do it!

I wouldn’t think twice about reusing a quicklick (or using multiple quicklinks in a chain).

I’ve broken 11spd chains where I’ve rejoined and broken a reused quick link (one that said single use). However KMC now offer a multiuse 11spd quick link. Will be using those from now on.

within reason yes

I didn’t even know Shimano made a Quicklink!!

Officially no, but practically yes, multiple re use has seen them fail when removed in my experience.