Leigh, I’m happy to share my experiences so far. What growing zone are you in? I’m in 9b, but most perennial collards and kales can go down to zone 6 or 7 just fine.
They can either be staked up or are quite happy to ramble along the ground. I stake mine to keep them out of reach of the wild turkeys that frequent my orchard.
They are especially delicious this time of year because the cold weather increases their sugar content.
I’ve experimented with growing out 50 different perennial greens each season, saving seed from my favorites, and then planting that seed the following year. At this point, I have 7 perennial kales and collards that I’m really excited about.
I’m hoping to stabilize their genetics and be able to share them soon.