Thank you for your reply, LenaH.
However, the document you linked to supports my assertion that the Q1 estimated tax due date was postponed until June 15 for some taxpayers, and I'm in that group because my 2018 tax liability was less than $10k. See the second paragraph of SECTION B which explicitly says that Q1 2020 estimated taxes for that group will not be assessed interest or penalties if they are paid by June 15.
Here's another document that makes this clearer, particularly in the table at the top of page 3.
It doesn't matter what the DP-10-ES says. The NH DRA rules were changed for 2020 estimated tax payments, and TT currently doesn't handle this situation.
