To address this issue more deeply, we have to look at the ontology of yom tov, and where it is situated: with the community, or with the individual? SPOILER ALERT: I'm going to claim that it's some of each. (These thoughts are relatively raw, and refinements are welcome.)
In that post, I wrote "This is an issue that will become more and more relevant in the future, due to various trends resulting in more intermingling between 1-day and 2-day people," and one of the trends mentioned (hat tip to JGN for this one) was:
the increased incidence of "shulhopping" (individuals participating regularly in multiple Jewish communities, and thereby having a greater need to define their own practice and identity rather than adopting a single community's practice)If people are part of just one Jewish community (particularly if it is the only Jewish community they have ever been part of), they are less likely to have to give any thought to their personal minhagim, on 1-day vs. 2-day yom tov or any other issue, since they are more likely to just go along with the community's practice, whatever it is. Now that people participate in more communities, whether simultaneously or serially, it leads many of them to be more thoughtful about their own practice. I think this is mostly a positive development, since it contributes to a world in which people are more deeply engaged with and invested in their Judaism. But when taken to certain extremes (in either direction), it can become incoherent, as I'll discuss in this post.
The extreme manifestation of this individualization of Jewish practice can be found in the discourse of Stage-1 pluralism. (Just to be clear, when I say "individualization", I'm not talking about Sheilaism. What I mean is that if you find yourself in the desert for Shabbat with no other people around, you still keep Shabbat, without a community.) In Stage 1, the discourse is about what is forbidden, permitted, or required for the individual, and various properties of communities become projected onto the individual. For example, rather than talking about egalitarian and non-egalitarian communities, we can now talk about egalitarian and non-egalitarian individuals, even though this concept is mostly meaningless outside the context of a community, and even though the specific communal practices in question have their roots in concepts such as "kevod tzibbur" (the dignity of the community). Stage 2 is fundamentally similar in this regard, but more toned down.
The opposite extreme is in some non-pluralistic communities, where the community is seen as the source of all Jewish practice. This is manifested most not in the Orthodox world (where the concept of individual minhagim is alive and well), but in the allegedly individualistic Reform movement. Perhaps the most extreme example is in those Reform communities that do havdalah before dark on Saturday. The underlying assumption enabling this is that Shabbat exists only in the context of the community, and therefore the community has the power to determine when Shabbat starts and ends. There is no consideration that an individual might have a Shabbat practice that transcends the community (and therefore is not subject to the communal decision to end Shabbat at this time); that simply isn't the conception of Shabbat as understood by that community.
I think a happy medium can be found in Stage 3, in which the identity-based discourse includes individual identities, communal identity, and the interaction between these.
So with that in mind, let's look at the ontology of yom tov. Yom tov is an aggregation of multiple elements, some of which are situated with the individual, some with the community, and some are ambiguous. Here are some examples (looking only at the 3 pilgrimage festivals), but this is not a complete list; other examples are welcome.
Elements of Yom Tov Incumbent on the Individual
- the prohibition on work
- kiddush and havdalah
- the yom tov prayers
- dwelling in a sukkah (on Sukkot)
- eating matzah and maror (on Pesach)
- not eating or owning chameitz (on Pesach)
- not wearing tefillin
Elements of Yom Tov Incumbent on the Community
- "Simchat Torah"
- Torah/haftarah reading
- reading of megillot
I think this dichotomy among elements of yom tov is useful in thinking about 1-day and 2-day communities, on the one hand, and 1-day and 2-day individuals, on the other. An individual who observes n days of yom tov should hold on to the elements in the first category (as applied to n days of yom tov) wherever s/he happens to be, whether in a Jewish community that observes n days, in a Jewish community that observes (3-n) days, or not in a Jewish community. See, for example, the one-day-yom-tov person's guide to the second seder.
On the other hand, the elements in the second category don't follow individuals around in the same way. For example, it doesn't make any sense for a 1-day individual located in a 2-day community to say on 22 Tishrei, "Today is Simchat Torah for me." If there's no community doing the ritual of Simchat Torah, then there's no meaningful sense in which it "is" Simchat Torah. (If a Torah falls in the woods...) To take a more obscure and convoluted example, many communities read Kohelet on Shabbat Chol Hamo'ed Sukkot. In years in which there is no Shabbat Chol Hamo'ed Sukkot (because yom tov falls on Shabbat), 2-day communities read Kohelet on the Shabbat that is (the 1st day of) Shemini Atzeret. In order not to make the long Simchat Torah service even longer, 1-day communities read Kohelet on the Shabbat that is the 1st day of Sukkot instead. But if a 1-day individual is spending the 1st day of Sukkot (in a year when it falls on Shabbat) in a 2-day community, it doesn't make sense for him/her to say "My minhag is to read Kohelet today", or conversely, if a 2-day individual is spending that day in a 1-day community, it doesn't make sense for him/her to say "My minhag is not to read Kohelet today". This is because there is no individual minhag to read Kohelet (in a ritual context); this is only something that communities do.
Ambiguous Elements of Yom Tov