Peace
I still can't find any information on Yuz Asaf outside his alleged connection with Isa (AS).
Even more so I have also found that Mirza Ghulam Ahmad had suggested two other sites as the burial site of Isa (AS) prior to this one. One in Al-quds and the other in Al-khalil.
Yes as a "prophet" receiving "divine revelation" mirza had to do some guess work, then he found a "holy" grave in Kashmir and labelled it as Isa(As)' grave.