Pretty clear that the Rasha Yeshu in the Gemara lived generations before the one whose death was used by Paul to create a new religion.
Shiffman, Eisenmann, Golb, and several others can give a Jewish perspective on the historical Yeshu. Shiffman particularly comes from a halachic/rabbinic perspective.
Historically, it seems that he was possibly from one of the many families claiming descent from David (as every single leader of Zealot and other anti-Roman groups did). (I say claiming, not that he necessarily was, but its possible). It seems from some of the sources (questionable as they may be) which were not redacted by christian scholars leading up to the Council of Nicea that there’s a lot of charismatic but also political efforts in his purported actions. The Romans certainly saw him as a political threat – that’s why they used Crucifixion, not another form of execution. And the non-rabbinic Tzedokim also saw him as a threat.
It’s hard to see a real historical figure through the shadows and curtains of Pauline christianity. There are some primary sources such as the Nag Hammadi scrolls which didn’t get censored and redacted by the church and have a less obscured perspective.
In any case he DID arrogate leadership and DID assert a messianic claim (not the only one in the era to do so) without the support of any significant Rabbinic (Perushi) leader. Like the others, he did not fulfil the criteria of a Jewish messianic leader according to the conditions described in the Neviim. This made him a failed mashiach (like Bar Kochba, for example).
I don’t know of any rabbinic or halachic sources which tell us to honour failed messianic claimants, and to “honour” the manufactured man-god that Paul created for sure not, so I’d say its a pretty clear NO to participating in christmas (Which, until the 4th century, was a pagan holiday called Natalis Invictus, the birth of the invincible sun, anyways until the church decided it would be a good way to bring in pagans by conflating their holiday with Paul’s manufactured deity).