Ok my FLAPS (NAPA) can only get the butyl in 1/4 round. The guy was nice enough to look it up in the catalog and all that shows up is round sizes. Is it ok or safe to use this style of sealant?

Go to a body shop/ paint supply store, or a glass shop and get what you really need. Flaps has to carry so much generalized inventory, they just don't have room for a lot of specialized stock like butyl tape in several different sizes and urethane tubes (my preference for windshields).