Can you modify a dumb waiter to be integrated as the hopper within the upper cabinet that can be lowered underneath the cabinet to the countertop level? Obviously, the dumb waiter would not be traveling floor-to-floor, but have limited travel from upper cabinet to countertop. Design the chute portion to sleeve "inside" the dumb waiter's hopper to prevent the catching of clothes on the hopper edges. Since you do not give floor-to-ceiling or upper-to-lower cabinet heights all the above is pure speculation on my part, but you get the idea. However, going to that extent only leads me to have the chute drop to a hopper that is ground level to begin with. You have netting sides for the ceiling-to-hooper span or a false upper cabinet front with netting from beneath to the hopper. Put the hopper on wheels to facilitate easy hopper movement. The hopper can be designed as a false lower cabinet (with wheels) too.

I grew up in a large house built about 1900. The laundry chute was in a cabinet in the hall bathroom, went down into a kitchen cabinet by the sink (so we cold throw dirty tea towels into the chute), and past that point to a large wood bin that could collect and hold the week's laundry for a family of 6. I found it useful. The chute built in my tract home goes from the upstairs hallway cupboard to the first floor laundry room small cabinet and could never hold a week's laundry for our family. It is too small to be useful. So we just use that hall cabinet to store extra pillows and the small laundry cabinet to store cleaning and laundry supplies.

I think you need to start over. A house is not like Lego where one can just keep adding things/changing a wall here and there. Each change affects so many other things. I cannot imagine having my MBR right off a very public space. I'm not big on 1st floor masters anyway, but if I had to have one, it would be in a separate wing of the house, separated from the rest of the house by a hall. I'd put the laundry in the mud room and a clothes chute from the 2nd floor to that room. You can always have a closet that could be turned into a 2nd laundry near your room when your nest is empty. There are just SO many things wrong with this house! It was designed for a small lot in a subdivision and you're putting it on 5 acres. The same house will not work on both. Please do yourself a huge favor and find a true architect to work with you to design a house you can enjoy for many years to come. Right now, you're just making one major compromise after another - not good for something SO expensive and so long-term.

How many people are you doing laundry for? There is just the two of us, and I have a hamper in a closet in the master for my more fragile things. A BIG built in hamper in the laundry room for all else. I seem to do laundry about twice or so a week (every three-ish days) and I sort onto the floor, or delicates into the empty laundry sink for a hand wash machine cycle later. DH folds and takes things back to the bedroom or appropriate bath...each bath has its own color towels so he can't mess it up. When I was newly married, I worked in the office of an appliance store that had its own in-house 'maytag man'. He taught all of us to do laundry. You didn't mention clothing/fabric weights when mentioning how you sort. That was one of his strict rules for not adding extra stress or wear to clothes. Sort not only by colors but by fabric weights. No navy shirts in with jeans or the shirt would be abraded by wet denim etc.... Maybe that's intuitive to most but my Mom really didn't sort. She had lots of strong skills but laundry wasn't one of them.