AMD implemented this kill-switch with "OC mode" which is enabled when you go >XFR ratio.
The problem with the kill-switch is that you can no longer benefit from Core Performance Boost features. Specifically, having a higher core frequency in single thread. In OC mode you can only sync all core ratios, meaning that you are limited by the maximum stable overclock using all cores. Practically, it's possible that your single threaded performance is lower in OC mode because your all-core max stable frequency is lower than the XFR single threaded max frequency. The only way to not have this issue is by using reference clock and using CPU ratios lower than .
On Threadripper this will be even more pronounced since we now have 16 cores. It will be interesting to see the performance and power consumption results comparing overclocking via manual OC mode and using reference clock.