I read your linked post, seems you didn't give it much running room to find a solution, but your decision. DaVinci Resolve 16 beta 1, although running pretty smooth for me, it's still beta and will probably be a couple more beta releases before they publish the version.

There are a whole lot of people that run VP16 without issue and a few that seem to have complicated issues. What is consistent between them is the Vegas Pro 16. Mine is the same as yours and everyone else's (if our builds are the same). What is different is our systems and source media and any optional add-on's. That tells me, the problem may not necessary be in Vegas Pro, rather what Vegas Pro has to deal with and sometimes the solution takes a while.

If you do not have those issues with DR16, and you don't trip on any different problems (every NLE has some problems) and you like the program, your choice has been made and the best of luck with it in the future.