Can you upgrade the fan?

Sadly Apple doesn’t use the same fan setups between the major series hardware changes. In your case the 2016 thru 2019 share the same fan. The 16” 2020 uses a different fan setup.

Frankly, you have a way to ramp up the fan as is! I find this App very useful! TG Pro it will allow you to visually see what is going on with all of the thermal sensors within your system as well as the fans RPMs you can ramp them up when things get toasty!

But, before you assume that is the answer it’s not! Often the fans and heatsink fins are loaded up with dust and pet fur! So you should clean things up internally. Get a small soft paint brush, a can of can’ed air carefully pull the fans out brush down the surfaces and use the can of air with short blasts to push away the loose stuff don’t race the fans as you can damage them.

And clearly making sure the vents aren’t blocked when sitting on a bed or rug.