"only a one time deal in 2010?"

Yes. I seem to recall we reported it for 2010, 2011 and 2012 as "carryover rule." That wasn't related to disaster.

"In 1099-R "less common" input screen, I found "Elect not to average over three years", this is only applicable to Qualified Coronavirus-Related distribution?"

Yes; look at form 8915-E. The default there is "over three years" so the Option is, "I report it all and pay the taxes in full for 2020."

And there is the provision for three-year repayment, as well, which means you amend from 2020, forward.