This is a hotly contested topic in E”Y. Rav Elyashiv is quoted as saying (that does not imply that he said it) that someone who moves here should stop putting on Tefillin on Chol HaMoed.
However, Rav Tuvia Weiss, the head of the Eida Chareidis told me personally that he puts on Tefillin on Chol HaMoed privately and cannot believe that there is a Rav in the world that could tell someone whose Minhag is to put on Tefillin, to discontinue doing so. I told him that there are Rabbonim that so instruct and he said that in his opinion they have no Heter to so Pasken.
I myself have davened with the Erlauer Rav in Katamon in his Minyan of Tefillin wearers. I go there almost every 1st day of Chol HaMoed. The other days I daven with the Viener Minyan (they are a branch of the Schiff shul in New York) of Jerusalem. Their Kehillah wears Tefillin on Chol HaMoed and they have a Minyan for that purpose with the express permission of: Rav Shmuel Wosner (of Bnei Brak), Rav Nosson Gestetner (of Bnei Brak), Rav Ulman (of Bnei Brak), the Erlauer Rav (in Jerusalem), Rav Scheinberg (in Jerusalem).
Rav Binyomin Hamburger of Bnei Brak has a Minyan where they wear Tefillin on Chol HaMoed. There is also one in Beitar.
According to Rav Hamburger, anyone who is of Ashkenaz persuasion should at least put on Tefillin privately at least out of doubt, because it is a shaila of a Safek D’oraisa and according to many opinions, one who misses putting on Tefillin even one day may get the title of a Karkafta D’lo Manach Tefillin.
Anyone who is interested in joining such a Minyan in the future or is interested in organizing such a Minyan in his area is asked to write to <[email protected]>.
The Pupa Rav zt”l (a well-recognized Rav in Jerusalem at the time of Rav Yosef Chaim Sonnenfeld) has a Minyan of Tefillin wearers on Chol HaMoed.
Rav Gedaliah Eisemann (Mashgiach of Yeshivas Kol Torah) always put on Tefillin in the Ezras Nashim of the Yeshiva.
Rav Nosson Tzvi Finkel of the Mirrer Yeshiva instructs those bachurim with the Minhag to wear Tefillin on Chol HaMoed, to do so in the Ezras Nashim of the Yeshiva.
Rav Scheinberg goes on record to say that there is no such thing as Minhag E”Y or Minhag Yerushalayim today because it is today one huge “melting pot”.
In Toronto, Rav Shlomo Miller does not allow a non-Tefillin Minyan in his Kollel building.
The uncle of the Beis Yosef writes in a Tshuiva that in Spain, before the popularization of Kabbalah, the custom was to wear Tefillin on Chol HaMoed because they followed the Rosh in everything.
Therefore, no Ashkenazi should follow the cue of the Sefaradim, just as the Rosh did not, saying that his customs were more well-rooted that those of the Sefaradim, because his Torah was heritage from the Chachmei Ashkenaz and Tzorfas since the time of the destruction of the Beis HaMikdosh and that they had an uninterrupted established Yeshivos since then, a claim the Sefaradim could never replicate.
Have a Godd Yom Tov
SR