Hello. Yes, maybe using tape is good this large, but it does somewhat depend on your painting style, right? If you are comfortable with large washes, or have become painting back to front, you will be comfortable not stretching perhaps. But really, stretching does help you a lot with your work, this large. Maybe you have used a Plexiglas support, in which you can use a really saturated paper, paint loosely—or paint really wet, and while it dries, keep up with the wet to dryness ration, and paint lose to tight? So many ways to paint and use watercolor, really. Depends on what your plan for the result is going to be, and your experience.
Stretching is not hard, and gives you such a beautiful surface to paint on, easy to control, and you gain experience. Did you know you can wet the backside of a painting, and lay it on your ironing board, and steam iron the rumples out, leaving it flat and ready to frame?
So many options, Jump right in!