I saw a suggestion to try adjusting the x-y contour compensation until the button cap stems have a better fit and since then the caps have lasted without issue. I printed 4 buttons subtracting -0.03 more on each iteration. I found the best fit and that's what I'm using on my flatbox. Credit to marsherino who discovered this adjustment.

These buttons felt nice but they didn't last long. I tried both PLA and petg but they eventually broke. Any luck with the buttons?