The purpose of the clip is to raise the needle out of the seat when the carb bowl dries up. This insures that residue from the drying up process doesn't "glue" the needle into the seat and prevent the bowl from filling on the next start-up.
With this new fuel, it evaporates quickly and leaves nothing behind in terms of "sticky" residue, and I haven't seen any issues to date by leaving the clip off the needle.....Cliff