Check the side of the plate. It probably says PANS-OPS 5.
PANS-OPS 5 now caters for constant angle non precision approaches.
If it says DA on the chart, use it as an DA. The loss of xx ft after initiation of the G/A has now been taken into account. There are not many procedures which are PANS-OPS 5 now (Europe) so the MDA+50ft is not completely a thing of the past.
Regards