Completed my first T17 map. I had no idea on the mechanics on the boss as only fought him twice in Expedition, so the fight was a complete mess. However they do not have a ton of health so was able to use the 6 portal defensive layers!
I stupidly ran this on my destructive play tree so had top had mods! you can make these much easier by adding things like Nico and Shrines to the map
Overall if you are willing to spend a few chaos rolling the maps these are definitely doable on the character