First you say it isn't overclockable then you say BCLK overclocking. SMH. I have overclocked my i3-6100 to 4.25GHz with the exact same motherboard I bought since 2016, which was my first pc and at that time I had no idea what overclocking was about, without any need to update BIOS. I have an ASROCK Z170 Pro4S. i3-6100 is a non-k meaning intel has locked it's cpu multiplier so the only way to overclock is adjusting bclk which affects not just cpu frequency but also memory and cache and fclk frequencies. There is a detailed guide here I have linked below. Don't be intimidated, oc is easy. You will get blue screens and black screens, be calm this is a normal process of overclocking. For my motherboard, there is something called "Press X to enable x boost sky oc" which overrides the intel microcodes that lock your cpu at your stock speed, in this case 3.7GHz. It's important to make sure that your specific motherboard is able to overclock/ override intel's microcodes that lock non-k cpus from being overclocked. Also, if you get comfortable with overclocking you can delid your cpu to get much lower temps and maybe even a higher overclock or quieter fan. You don't need a 40 dollar delidding tool just a simple razor blade, liquid metal, and nail polish.
https://www.tweaktown.com/guides/74...e-intel-skylake-overclocking-guide/index.html