Yes, I have reset t2, smc, nvram, even reinstalled the entire operating system. I have the same problem on both 16 inch laptops I've owned (first one was stolen) suggesting it has to do with the software I use.
I am unable to identify a single application as the culprit, unfortunately.
Yes if you have such issues on two different machines it is most likely software rather than hardware.
It is frustrating and time consuming but have you gone step-by-step on a clean system to at least narrow down when the issues begin to occur?
I know it shouldn't be needed but sometimes it is the only option.
It isn't much help to you but my experience with Catalina has been very positive on a 2018 15" MacBook Pro. The initial release and first two point updates had some silly UI bugs but since .4 it has been solid as a rock for me.
I just updated to .5 and noticed I haven't had to restart my laptop since the last update I installed 42 days ago. In those 42 days I haven't had a single issue so I am pretty happy about that.