if i wasn't blowing it apart for paint i'd do the jambs and then the outside separate.otherwise the chase is on to keep things wet and all.sure it's more work because it's double the time/masking etc etc but overall(myself)it'll come out better.i'd jamb everything,hang it all,estabish my lines(as it never goes the way it came apart)and spray the outside.keep in mind all those paper folds,crevises,seams,anyplace where paper/plastic meet can form pockets that when they're hit with psi will move and posablly kick up dust.those areas hold dust.try and "pull" the plastic together,as in make it as tight as you can.pull it tight and tape it to itself.you want it taught.do a dry run,blow it all down with air and see how your masking behaves.that will show you whats going to move when you're actually painting it.it'll show whats to loose and where these areas that can trap are etc.that said keeping a roll of tape handy is away a good idea.