I use / and reuse / and reuse / and reuse... SRAM powerlinks and KMC 10 speed links (and 11 speed links as well on my mountain bikes). I wouldn't think twice about reusing a link. I do find anything over a 9 speed I have a tool for removing and properly seating.

I picked up some KMC 10-speed links the other day, and they specifically called out "reusable" in big letters on the package. I believe Wipperman is the same, and also they are designed to be removable by hand, although I haven't tried that in person.

I read something interesting recently on one of the forums, that the quick links seemed to wear more quickly than the rest of the chain. The poster was saying that when measuring a random length of chain, the wear was fine; but when measuring a section that included the quick link, it measured as completely worn out. So it wasn't that the link was weaker per se, but reusing the same link for ages might accelerate drivetrain wear.

Wipperman Connex links. They are available in 9, 10, or 11 speed. They are designed so you can take them on and off with no tools so there is no issue with reuse. I've been using them for years and have never had a problem with them.

I'll second the conex whipperman link. It's the superior product. No tools necessary, and no limits on reuse.

https://www.connexchain.com/...uct/connex-link.html

I re-use them as well, probably as many as 10-15 times, but get a new one when putting on a new chain.

I've been using Wipperman Connex for years - can take them on and off with your fingers, no tools needed