I'm a bit confused why you add 50ft to LNAV/VNAV or LNAV minima.
I thought you had to add 50ft to an MDA to set it as an DA and fly an DA style approach.
Since most LNAV/VNAV and in Europe also LNAV have published DA you don't have to add the 50ft anymore. (I thought anyway) since the publisher of the plates eg. Jeppesen allready added the 50ft to calculate the DA minima on an approach.
That's why the LNAV/VNAV DA minima on the plate above has hight er minima as the LNAV MDA minima. Would be silly if the LNAV/VNAV approach had higher minima as an LNAV only approach.