Any status update ? Just tested the OneLocker app (https://www.microsoft.com/store/apps/9nblggh3t7g3 ) and this app supports the full Windows Hello feature meaning that when the app is closed completely, you can unlock the app with Windows Hello on your Lumia 950 or 950XL without the use of a master password.
For now I'll stick with Enpass, because I bought is 3 times (2x Windows Phone, 1x iOS) but I think it takes a long time to implement the full Windows Hello feature.