Same here I've only broken chains, but I've never broken a quick link be it Shimano or even the cheap ones. The SUMC and Rider Ace quick links can be bought in bulk. They seem to have a shorter use life, but you can have like 50 of them for not much money.
I have been purchasing the Rider-Ace quick link 5 packs when they are on sale for $1.79 or $1.99. I have a few in use, and none have had any issues. This being written: My usual chain routine is... When I install a new chain, I use the supplied quick link (Usually KMC chains) to first set up the bike. The quick link that comes with the chain gets installed and removed 2-3 times, but not ridden under load. After the chain is the correct length, I remove the new chain, clean it, immersive wax it and then final install it on the bike. Then I leave the chain on the bike, regularly adding liquid wax. After it starts to look dirty, I remove the chain, clean it and immersive wax it again. (I do this 3-4 times a year.) When I install the chain back on the bike, I use a Rider-Ace quick link. On average, I end up replacing my chains about 1 to 1.5 years. Therefore, I go through 2-3 Ride-Ace links per chain on a bike. I've been consuming around 8 to 10 Ride-ace links per year.