If you keep one day YT and intend to stay in EY, then you should stop wearing tefillin on Chol HaMoed as you are ??? ???? ????? (as I have done). If you keep two days and intend to return then you should put on tefillin at home privately after davening, since you are still obligated by your original minhag but since NOONE in EY wears tefillin Chol HaMoed it would be ?? ??????? to wear them in shul.
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