So Lucky, I have tried for years to come up with a "summer hardy" member of this family. A guy originally from Louisiana and who works with a neighbor saw my Portuguese kale in 2014. "Oh! Is that collards?"
When he showed up in the spring of 2015, I gave him some kale plants - Scotch kale.
I have resigned myself to Scotch kale, mostly. (What
@Sweetcorn calls "green cardboard"

). The young leaves are pretty much okay, right through summer.
With the record heat, the Portuguese kale quit on me in 2015. However, it seemed almost bullet-proof until last year. There was a larger variety of kia-lan, South Seas, that worked fairly well through more temperate summers but didn't in 2015. Broccoli raab has had good and bad years.
Yes, a healthy, big, leafy brassica would be welcome in my summer garden - a biennial would be nice. It is a little too arid and hot here for them. I'm sorry you didn't have a better experience in Missouri.
The bugs like all of these things. Aphids are the worst for me and, because of the way it grows, cabbage can have huge problems. The wrinkles in Scotch kale give the dang things plenty of places to hide. I thought that the smoother leaves of Russian kale would be a better choice but aphids must relish that rutabaga relative!
I had also thought that collards needed and cruise through summer heat and that we don't have enough of those weeks of that kind of weather here.
Steve