Hand stitching is ( often) quite difficult through fusible. Generally the two techniques are { fusible- raw edges, machine stitched} ; [hand stitched- needle turned; finished edges]
That doesn't mean you can't give it a try. Your hand stitching will need to be very close- to keep those raw edges from fraying, coming up. I would fuse a (sample,practice) block and try it out before committing/ trying it on the banner. If possible use the same background fabric, fusible & applique fabric on your practice piece. A good, sharp new needle will help. Also the type of fusible used will play into the success. You might need to clean goop from your needle often and change needles as they dull- depending on how much you plan to hand stitch. As for it being ( OK to do) sure, people mix techniques all the time, hand and machine applique, hand & machine quilting, hand and machine piecing.... Just do a practice piece First to work out the details.