Covers band turns into originals band while playing Dog'n'Duck gigs is a well worn path. The better you are as a band the easier it is to pull off.
So far you have got to the stage of one hit wonders in your own Dog'n'Duck.
I would be voting for churning out more original stuff and inserting the new tunes regularly, but dropping duds like hot rocks.
Any cover gig can stand one original per set. Work your butts off to increase the number of your own solid gold hits to two per set. Then you might be getting festival slots.