Someone wrote me privately that the link I provided is for Roman Catholic records.
IT IS NOT!!
Metryki Genbaza recently updated their website, redoing their entire file structure. How they have labeled their files, and how they have combined their Jewish vs. Christian files is not our concern.
If you go to Metryki Genbaza https://metryki.genbaza.pl/index/list and put the town of Lask (or many other towns!) into the search engine, one of the choices is Lask-moj (the Jewish files) which is combined at the bottom of the regular Lask files (the Roman Catholic ones). (If you just put in the town's name, without moj, if they have scanned and provided the moj files, they will be at the bottom of the long list of regular files for the town in question.)
Once in the Jewish files, any person can review each and every year and the indexes that are in those years (births, usually followed somewhere later on by marriage indexes, then death indexes at the end).
I only looked at 1892 as that was the year that was originally discussed.
In looking at the index for births for 1891, https://metryki.genbaza.pl/genbaza,detail,278627,39
I don't see Jakov Aron names, but anyone is free to look at the Metryki Genbaza files. They are no longer requiring sign-ons.