Just be aware that the form 2210 is not ready for filing (efile or paper) yet, and yes there are computation errors on it. At this point when I open one it says ready 2-17, so we will see. If you look at part III you will see that it still has payment due dates of 2020 rather than 2021.
Probably want to wait a few days and see if it does get updated this week.
Iron Man that may be the solution there if the estimate dates aren't fixed , , I.E. we can have the clients increase their withholding, if possible,, instead of giving them estimates...