have you perhaps comtemplated about making USNO-B1.0 accessible in SkySafari? Of course I don't mean an offline access (80 GB, my God...) but something like the connection to the DSS database. Maybe a button which make the app download and show the stars from USNO in the current FOV.
(I understand this may conflict with the UCAC5 in-app purchase, maybe this could be an another purchasable item)
Have a beautiful day! :)