I cant remember the last time I needed to call support, so I have no experience with phone support reps at all.

When I first installed 2020 it started printing duplex for me as well (hate that!), but its not a Proseries option to set, you have to change it in your Windows printer settings. Once I unchecked that box, I didnt have anymore issues.   To print all the ES vouchers at once, I just choose Print Preview, and only check the forms I want to print, easy peasy.

Yes the tax law changes automatically changing the returns is a hassle, Ive been locking the file after its accepted, so if I open it again just to look at it, its still the same as when it was filed.

Thankfully the majority of my clients preferred to wait to see if the UI exclusion passed prior to filing their return...I think I only had 6 or 8 that we filed prior and IRS will correct those automatically, so no amendments for them.  IRS is automatically adjusting for the APTC exclusion as well, so no amendments there either.