It would be fine to confer with the Jews (every time I use the word as a reference to religion, not ethnicity) in a way that does not include worship, for we do not worship the same. Like I reminded the reader several times, we pray to the Crucifix as the image of God. They don't. Communal worship is thereby impossible; however, if it is watered down to the point that there is no Crucifix, then that is the validation of the precise error of modern (past 2000 years) Judaism.
Very nearly the same applies to the communal worship with the Protestants, as comments coming from them on this thread amply prove.
Both groups should be invited to the Catholic proper worship, which is the Holy Mass, but the intention should be evangelism and not common prayer before there is a conversion.
Jesus Christ instructed his followers to pray as he did ( to the one true Creator God he and his fellow Jews prayed to then and now). Respectfully , but Praying to a crucifix sounds very much akin to Abraham praying to his father’s idols. Or the liberated Jews praying to the golden calf they’d fashioned in Sinai. We do not pray to idols. We pray to God. Blessings