The Ideals are about 2/3 the size if full depths. My TBH takes full depth. I could put the ideals in, but I fear they will make a mess in the gap below. So I had pkanned on doing cutouts, brood abd all, and place them down the bottom of the full depths, leaving perhaps a 3 inch gap at the top. I was hoping they would build new combe down to it and everything would be OK.\ The other alternative is to still do cutouts, but attach them at the top, with nails through the sides. Would they attach it properly ?
I think you're much more likely to get a mess with the cutout. In my experience, bees don't like to connect down to loose comb nearly as much as they like to draw down from properly attached comb. It will probably suffice, but the cutout seems unnecessary.
My recommendation: put the ideals right into the full depth TBH. They usually build neat comb hanging down (as they would from any bar) so I don't see this being a problem. If you want the combs to be solid all the way with no bottom bar, then cut just the bottom bars off the frames before putting them in.