My late bloomers are some of my favorite irises.
Right now I have Cajun Rhythm, Coral Chalice, No Count Blues, Walking on Air, Attractive Lady, and Jennifer Rebecca just starting.

I also have Spin Off, Maid of Orange, and Beverly Sills, which all get a few stalks in the first week of May then bloom big the first week of June here in California.

Renee

Welcome back to gardening! I'm not the most knowledgeable, but my iris that bloom later for me and aren't rebloomers and do well are Full Tide and Sheer Bliss. I am hoping someone with more experience who lives in a place closer to your zone will chime in. Most of my iris are not new ones. I have two that are listed as rebloomers that bloom for a very long time but have never tried to bloom in the fall so they have done okay for me are Superstition and Spiced Custard. They start well before the first two, and continue to bloom while the first two are blooming, except Sheer Bliss is always the last to have blooms.

Thanks for the feedback. Much appreciated.