I agree that the Heat Treatment process doesn't do any 'harm' to any tobacco, except darken its colour. It does however, appear to 'gum' the leaves together inside a one pound package and it often requires some patience and the application of water spray, steam, etc to recondition it to a point where the leaves may be easily separated. Having said that I have found that same 'gummed together' condition in packages that have completely escaped treatment so I'm far from certain that the process is entirely to blame.
On the matter of Maryland I have found that it generally comes through in much more easily managed condition than with the flue-cured choices. However, I've also found that it isn't always at its best straight out of the packet - it often needs a few weeks 'aging' in the open air to eliminate the sometimes noticeable ammonia scent.
I generally shred mine straight out of the packet and leave it sitting (airing), shredded, for as long as I can before blending it with various Virginias and Prilep.