Hakatan- chalav Yisroel is a chumra in the sense that there are reliable poskim who don’t require it. Unless you don’t consider R’ Moshe a reliable posek. Chumra does not mean unnecessary or even optional. For those Jews who have poskim who are machmir are certainly required min hadin to follow that psak.
But since every frum Jew has a right to rely on their posek, assuming that that poske is reliable, I find it hard to believe that it would be a prohibition of lifnei iveir to assist or even enable a Jew to rely on their psak, even if your posek rules differently.