I go to a Reform synagogue every week on Saturday morning, and about once a month on Friday evenings.
I don’t keep kosher, but that’s not something my synagogue (or the movement) teaches against, and I do it as an actively Reform Jewish practice. Eating non-kosher food (especially flagrantly non-kosher food like pork and shellfish) to affirm rationality and disavow doing superstitious-like actions with no meaning to the practitioner has been a strand in Reform Jewish since the 1885 Pittsburgh Platform. (Which isn’t to say that eating kosher is non-Reform. My synagogue’s stance is, if it is meaningful to you, eat kosher, if it isn’t – or if it is meaningful not to – don’t eat kosher.)
I also oppose circumcision, which is more broadly practiced in my particular community than keeping kosher, but also doesn’t contradict any official “doctrine” (inasmuch as there is one).
The position in UK progressive Judaism that I most disagree with is its stance on interfaith marriage. Reform rabbis aren’t allowed to preside over marriage ceremonies between Jews and non-Jews. The rabbinical college, Leo Baeck, won’t accept students with non-Jewish partners. Its argument is that rabbis and their families, if they have them, should be a model for the community for Jewish living, but I think saying that an interfaith family cannot be a positive model is extremely problematic.
A friend of mine is married to an Anglican vicar and would like to train to be a rabbi, but Leo Baeck won’t accept her. They would accept her if she were married to someone whose surname was Cohen but who never went to services and didn’t have any relationship with religion at all. I think an interfaith partnership with two people who are thoughtfully, actively engaged with their religions is much more of a positive model for a religious community* than a “fully Jewish” partnership in which one happened to be born to a Jewish parent but doesn’t engage with religion meaningfully.
It is the only racist policy I can think of the UK Reform movement holds, and it is extremely disappointing, because it is otherwise very progressive about converts, Palestinian rights, non-halakhic Jews (Jewish father but not mother), and other issues that are common sticking points in the more conservative branches of Judaism. I can’t see how there is any reasonable justification for it.
*I’m not saying they would be a more positive model for any group, or that thoughtful religious people are better role models than anyone else generally – only in the context of leadership of religious communities.