Miami departures and the Amex lounge

Looking at some flights leaving MIA back into LHR
I notice that VS now depart from concourse H and use the Delta lounge as opposed to the horrific lounge they used to use.
Would quite like to check out the new Amex Centurion lounge which is in concourse D - am guessing after security
Anyone know if it is possible to visit the lounge then return to concourse H or MIA being MIA, is it a right PITA !
many thanks
David
I notice that VS now depart from concourse H and use the Delta lounge as opposed to the horrific lounge they used to use.
Would quite like to check out the new Amex Centurion lounge which is in concourse D - am guessing after security
Anyone know if it is possible to visit the lounge then return to concourse H or MIA being MIA, is it a right PITA !
many thanks
David