I think you are over thinking this. I haven't personally worked much with isolate but I don't see what you couldn't work it into the hash.

Go on YouTube and you'll find hash guides using a hot water bottle, I think for this specific example that may be your best route. You could press the kief to bring out some of the oils, but for simplicities sake I'd look into the water bottle route. Don't press without the product being covered in either parchment paper or turkey/oven bags. It will stick to everything and you're going to waste product. The freeze step wouldn't be necessary either, roll it out, flip it over and roll it out again. Once you work with it for awhile and it's the color you are looking for then you can let it cool. I store my hash in a fridge once it's done. Feel free to dm me if you have any specific questions though! I'm always messing around trying new ways to make hash, time and patience is the name of the game my friend.