I'm chasing grid squares towards Satellite VUCC and other awards. Is it acceptable and good operating practice for my station to make multiple contacts during FD on the linear birds?

Make all you want on the linear birds! You'll no doubt hear stations and grids you normally won't, but I'll warn you, FD is chaos on the sats. FD stations can also be very difficult to get a QSL out of as well.

73, Drew KO4MA