Airbus Bloke
I'm not sure about what you wrote, and I'm not Bus driver,
but...
for what You asking for, Napd1 1500/3000 are heigh and you don't have to add the airfield elevation.
Then, what we use to do if your CDU report also the 1 EO heigh, at this time as per our Company policy for example minimum is 1000, we add the difference between this last and the MAFRA if higher than 1000, indicated in the T/O Performances.
hope this make sense..