Ah fair. The first century converts did do this. There was a small phenomena I know of where occasionally ex muslims would still use islamic prayer postures or prayer beads (likely originally Christian anyway) in regards to Christian worship, but most people want to completely shake off an old religion in regards to Christianity (and these cases I heard were actually secret converts living in Muslim households)

There would be an issue if it’s an anti-Jesus rabbinic Jewish tradition. Some believe the Dayenu might be this (which made me question it’s inclusion in The Chosen) but that’s another thing.