In terms of birur yahadus, there are many difficulties.
If a guy comes into a shul wearing a yarmulke, let’s say, there’s no reason to not count them in a minyan or give them an aliyah. If they want to get married, we have to investigate. The problem is, in an era of Reform and Conservative changing the halacha of Jewish status, geirus, intermarriage, mamzerus, etc., how do we really know? How many people can furnish a picture of their maternal grandmother’s matzeivah or kesuba? How many people have a conversion certificate, especially from years ago, when any 3 rabbis did conversions and those rabbis died and their shuls closed down? It takes big shoulders to deal with these issues.
In the case of Elk, the ball was dropped. How did he manage to learn Hebrew well enough to learn safrus and milah, get semicha, and somehow learn in a mekubalishe yeshiva?