Neither have I but I don't want to give it any reason to!!
I said the same thing to Don (the old guy I referred to earlier)... I said, "Don, you're not supposed to get into the drive-links!.. It'll weaken the chain!" He laughed at me.
Don has been in the saw biz for over 50 years... Unless you're really digging into them (like a dummy), there is no problem. I've been using a saw for 20 years, and he helped me hone my sharpening skills a lot. His hand filed chains are next to none for sharpness.
I've seen chains brought in by 'pro' users, and they're filing skills (more often than not) leave a lot to be desired. Don told me a story from back in the '70s... He had a logger bring a saw in for a tune, and Don saw how messed up the chain was. When the logger came into the shop to get his saw, Don asked, "Who taught you how to file a chain?.. It's horrible." The guy got miffed, and said his granddaddy had showed him how, and they were 6th generation loggers--blah, blah, blah. Don sat the guy at the bench, and filed his chain in front of him... Describing what he was doing, and why. The next week the logger popped in, and told Don he couldn't believe how well the saw cut, and asked Don to teach him how to file.
Point being, Don gets into the drive-links a little while filing... 50 years worth... Zero failures.
To each his own though.