How common was it for american synogogues to fly the “zionist flag” before the establishment of the Israel?

Sort of a weird question, but I was watching the movie “the Jazz Singer,” which for those of you who don’t know was the first movie to have a sychronized sound track and recorded singing.

It’s also a very Jewish movie, and there’s a scene during the night of Yom Kippur service where the community is singing the Kol Nidre, and towards the end of it you can see the flag of Israel/flag of the zionist congress in the background. The movie came out in 1927, so more than two decades before the founding of the modern state of Israel.

Growing up, my (reform) synogogue had an Israeli flag next to the American one, and I’ve seen other synogogues with a similar situation.

But now my question is how common would it have been for a synogogue to be flying the zionist flag/flag of the zionist congress at the time the movie takes place? Would this have been very common, or is this just something the director of the movie decided to include?