That’s the way I mean - it’s the switch stems that damage the cap stems, by virtue of being slightly too large.
Current Kailh BOX stems (and some others mentioned) will cause those little stress marks and even cracks on cheaper caps like those stock WASD ones - but the pre-retool stems would straight up demolish them, and I mean just about any cap, not just dainty stock ones.
Signature Plastics’ SA keys are famous for being thicc and chonky, but not even they can survive those initial BOX mounts - stems cracked completely open, falling right off of switches after that.
I have three unusable keycap sets (including one MT3 
) from a set of pre-retool BOX switches that had been mixed into a newer batch (some rando seller on Ali, I think); from that point I only picked up BOX switches from retailers at the top of my most trusted list. NovelKeys is a good source, and Kono still has some old ones for sale but has the good sense to label them.
SwitchCaptain is the vendor that probably goes the farthest when it comes to ensuring authenticity; every single pack they sell is individually tracked and tied to specific batch numbers from the manufacturers. If you get bunk switches from them, not only will they replace them like any reasonable vendor, they will know exactly which batch they came from and be able to communicate with the MFR about it.