I don't remember this being discussed before. When I try to run Furmark on my G752 VY DH 72, either full screen or 1024 it hammers my #1 core and it immediately goes to 100C GPU only gets to 75C ish . I checked on my G75 is Furmark does send a single thread to the 1st core of that CPU also but my fan comes on and keep it cool. I think the G752 VY fan may not be coming on for a single thread single core load?
BIOS is 213 Idle temps high 40's low 50's. I can run Test In 100% load to all four cores it never exceeds 75C in 20 minute burn in
Furmark version 188.8.131.52
G752VY-DH72 Win 10 Pro 512 GB M.2 Samsung 960 Pro 1 TB Samsung 850 pro 2.5 format 980m GTX 4 GB 32GB DDR 4 Standard RAM
Z97 PRO WiFi I7 4790K Windows 10 Pro Z97 -A Windows 10 Pro
I find the fan curve in the newer models are set higher in temperature points for even quieter fan operation than previous models had, which means higher load temperatures and even lower acoustics. NBFC is definitely key when using newer models I find.
You are correct about the single thread and core #1 being hammered (even the latest version does the same - tested). It's possible that more than 1 loaded physical core with uncontrollable thermals doesn't signal fan logic to intervene, but goes straight to CPU PROCHOT signal for package throttling. You'd need to do further isolated tests before that's even plausible though.
As you've stated, testing on all 4-cores is fine as thermals are controlled, never exceeding 75°C. Perhaps someone with your model can chime in and compare.