2019 MBP 16" 2.3Ghz i9 severe thermal throttling (Catalina 10.15.5) Brief Summary
2019 MBP 16&quot; 2.3Ghz i9 shows severe thermal throttling

CPU Frequency hovers around 1.9-2.0 Ghz
Power draw doesn't exceed 30W
Max Temperature only 76ish degrees Celcius
Exporting a 5min clip on Adobe Premiere Pro which slams all 8 cores

I've attached screenshots below showing just how much the new MBP 16&quot; i9 throttles.  I haven't really had a problem with it until recently... but there are 2 variables:
What's Changed?

Catalina upgrade to 10.15.5 recently
Applecare service replaced the logic board

Questions

Is it likely that the replacement logic board is not up to snuff?
I haven't heard any complaints online (reddit, stack exchange, apple support) of thermal throttling lately.  How does one test abnormal throttling?

Screenshots

terminal output after running pmset -g thermlog
intel power gadget showing the aforementioned stats holding steady despite high CPU Utilization.
Thermal throttling is normal behavior for laptops.  However, I did not expect the extent to throttling in everyday applications.
While Cinebench R20 shows robustness against thermal throttling, Adobe Premiere Pro thermal throttles right away.  The only explanation I can think of is that Cinebench R20 does not engage GPU while Adobe Premiere Pro does.  When CPU + GPU are both used in conjunction, thermal throttling happens immediately.
I suppose this is a limitation of laptops.