Ok which is it?

[pair of jacks]

The marina where I keep my boat will always block my boat right on the thru-hulls unless I specifically tell them not too. They say it doesn't hurt them which is the exact opposite of what I have always been told- so is it a bad thing to have the boat sitting in a cradle or on blocks that are right on top of the the thru-hulls? I have the usual ones: washdown, livewell fill, sounder transducer,etc.