Running CMake + gcc on a bigger project? The fans start running like crazy. The performance of the i9 is awesome, at least for the first 1-2 minutes, after that the CPU is throttling you back to the 90's and the fans are spinning even louder.
But this is not even the funniest issue with it. I have the biggest and most performant charger (96W, pretty much the maximum, because the USB-C standard states, you can only push up to 100W through it). You may think, if Apple put that charger in the box, it should be enough to achieve max performance with it AND still be able to charge it. Nope, but maybe it would be at least enough power, so the battery is not discharged. Lol, nope, higher load for a extended time WILL discharge your battery while being connected to the power supply.
I've tested it with two separate MBP with exactly the same spec (i9 + 32GB RAM + Radeon 5500M 8GB) with exactly the same behavior.