Aharon Einbinder Hopstein

Can someone please provide metrical documents that show the use of the name "Einbinder" during this time period it seems like "Hopsztein" should be the primary surname and "Einbinder" should be in parentheses or in the AKA box not vice-versa. . .

Additionally, what is the evidence that Aron is the son of Shabsi and an unknown other wife rather than Shabsi and Perla Laia