If you are using offsets, then that might change things a bit, if you are testing with no offsets but plan to use offsets after testing because obviously the use of AVX in games or applications would then not be likely to reach the same thermal peak as with it enabled.
For the purpose of longevity alone, I would certainly never allow a daily driver to be overclocked to a level where it is seeing, at most, 85°C. If you look at the data in the intel temperature guide you'll find that due to thermal degradation and VT shift it specifically says this:
If your hottest Core is near its specified Tj Max Throttle temperature, then your CPU is already too hot. The consensus among well informed and highly experienced reviewers, system builders and expert overclockers, is that it's prudent to observe a reasonable thermal margin below Throttle temperature for ultimate stability, performance and longevity. So regardless of environmental conditions, hardware configurations, software workloads or any other variables, Core temperatures above 85°C are not recommended.
And, that should be during testing. You don't want to configure your CPU to reach 95°C during testing "because you know it will never reach that temp in real world use" because actually, you don't know that. I and many others have definitely seen it happen. Now, if this was a CPU you were just playing around with and had no concern for whether it lasts or not, then by all means, cook it. But don't do it for any daily driver or valued system. Obviously, that is just my opinion, but it's backed up by a wealth of resources including the Intel temperature guide which I believe to be the definitive informational resource on Intel processor temperatures and specifications related to them. But of course, it's your CPU, you can assuredly make your own decisions in that regard. We simply make those recommendations based on what we've seen, experienced and in the case of Computronix, what his extensive testing has determined, to be the safe zone. Not everybody likes to play it safe, or safe-ish rather, so that's something you have to decide for yourself.
Keep in mind though, that unless you are monitoring CPU temps 100% of the time, you really don't know if at some point you'll run something that may exceed the loads your system normally handles which is why we recommend having a moderate buffer there.
You'll need to look through the advanced settings on the tweaker tab, but there SHOULD be a setting in there to set frequency per core. Also, I highly recommend disabling Intel Speedshift and enabling Intel Speedstep, along with setting the C-states to their auto settings or leaving them enabled. Again, that's up to you, but more often than not you'll see lower overall peak temps under identical loads if the core gets a chance to relax down to a minimal frequency and voltage when not needed, which will usually be periods of microseconds under good loads, rather than always being at a static higher frequency or not allowed to reduce below base clock speed as some people prefer. CPUs can go from 800mhz to 5Ghz faster than any person could notice the change so in that regard there should never be any lag and if you under a full on fairly continuous load it's unlikely that any core that is needed will drop it's speed anyhow.
Again, those are my preferences. You may prefer to do things differently. The reason I have some doubts on stability with those settings, and I'm not saying it is NOT stable, I'm just saying, do the work to be sure, is because of what I've typically seen others able to achieve stability at and the fact that my only 4 core 4 hyperthread 6700k requires 1.35v for a 4.6Ghz all core OC. I know there have been SOME refinements to the architecture since then, but not much. It is still Skylake 14nm architecture at the end of the day. So, four additional cores with a moderately higher overclock SHOULD typically require more voltage, but testing will tell you the truth for YOUR CPU because every one is different. And, as I said, there have been refinements since the initial 6th Gen Skylake products.