1 Is notarization recognized/used in Batei Dinim today or they have not much validity since there are not 2 eidim?
2 Do Beis Din today “mekayaim shtaros” as is discussed in Choshen Mishpat siman 46?
1. Yes, this is recognized because of the legal implications of notarization (similar to the idea of Shtaros or Arka’os as found in Gittin).
2. Kiyum Shtaros is not something which happens often, but in cases of claims of forgery and the like the principles of Choshen Mishpat 46 will apply.