I bought two bands of own-root SdPL from Burling in the fall of 2020, and actually had several blooms before the year was out. Next summer, I found that the plant I had in a somewhat shady area (ca. 40% shade) spent a lot of energy just throwing up 6 - 8 ft. blind canes, and had fewer blooms. This spring I moved it to a full sun position, and it is really thriving. No blind canes, much more compact and bushy, and covered in blooms through its first and second flush so far, and a third is just few weeks away. You might re-assess your position, if not in full sun.

I’m right at the 6a/b line.