What
@Queen6 wrote is all true, unfortunately doesn't apply fully to Razer. Everything is locked, you have three Synapse settings and that's it, can't change PL1 or TDP, PL2 is not used at all.
1. Your machine doesn't turbo at all, that may be due to some settings in Windows power options ->Advanced plan settings->Processor power management->maximum processor state (100%) and System cooling policy to active. Or may be disabled in Bios, or you messed with this setting in XTU. I don't know.
2. Don't use XTU, use throttlestop to undervolt only. Changing any of the power settings in it (or XTU) doesn't do anything.
3. You should be getting CB20 between 2600 and 2900 in Synapse Performance mode, depending on how long it stays at PL1. If you want more you have to mod the bios to unlock access to advanced options. Honestly it is not needed, that machine is perfectly fine even when limited to 45W. With -125mV undervolt I didn't see more than 55W @4GHz on CPU anyway in normal use, I think only small FFT in Primes kicks it more.
One thing I noticed, this may be a bug or really crappy attempt at 'balancing' load from Razer - out of the box, with Razer provided Nvidia driver, it would artificially add 10W to indicated CPU package whenever anything was using dGPU. Thus the machine would power throttle way sooner. And the CB20 attaches itself to dGPU (unless you force it to use Intel in Nvidia control panel) - you loose 10W immediately, so instead of throttling to 45W it would actually go down to 35. And the same with PL1 limits, 10W lower. I'm using drivers directly from Nvidia now and it is ok.
Check this out - run Intel power gadget and observe PackagePwr when you start CB20. Just start the program, do not run the benchmark. Is the package power magically 10W higher? Also select "Display GPU activity icon" in Nvidia control panel, to check if the CB20 is actually running on Nvidia.