[Avodah] Not saying Tachanun

[Michael Poppers via Avodah]

In Avodah V33n70, RZS responded to R'Micha:
>> I bet [RYBS] said tachanun on the Gra's or R' Chaim's (Volozhin or Brisk)
>> yahrzeit, etc... For people who are seeking his pesaq, it's very likely
>> he would insist on Tachanun on days like that.

> Of course he said tachanun on their yortzeits, why wouldn't he?  The whole
> concept of turning a yortzeit into a holiday wasn't native to his world.
> The question is what he would do on a day they had been saved from some
> danger, and had observed as a private yomtov, or on a day that his
> community had adopted as a local "purim" to commemorate being saved from
> danger, as was a common practise among Jewish communities.

...or on Pesach Sheini?