“while there is no chiyuv for a woman to be wearing Tefillin (b’tzniyus), there is no issur”
And that is the conclusion that one gets from today’s gemara. It concludes the discussion with a machloket tanaim between Rabbi Yosei and Rabbi Shimon permitting, and Rabbi Yehudah prohibiting. In disputes between Rabbi Yosei and Rabbi Yehudah we pasken like Rabbi Yosei.
Rishonim bring up other issues and there is an opinion in the Yerushalmi that the sages objected to Michal Bat Shaul wearing tefillin, but it is difficult to prohibit women wearing tefillin based only on the Bavli.
And in any case we do not follow the Yerushalmi in Eretz Israel regarding tefillin. Anyone who disagrees should try putting on tefillin at the Kotel on Chol HaMoed and see what happens.
Regarding tzitzit, there just isn’t any source in Chazal to prohibit women wearing them.