The reason, one of the reasons, I bring up the ductwork is taht if it is done poorly, as it was in my home, with the technology in the mini-splits you can remove the duct work and replace with mini splits. I did that and netted out two good sized closets and storage under the stairway. As well the building is zoned. I have a dual for the upstairs bedrooms and two very high seer singles downstairs. With the solar system I installed last year we are H&C for zero dollars. I burn some propane for my Rinnai wall furnace on one side of the house. As to the central units, I’ve been out of that end of the business long enough now to be shy of suggesting one or the other. A fellow I know and respect likes the multistage Carriers. From a comfort standpoint, you want at least two stage. I would not hesitate to use a mini in your shop or the house, IF you have the contractor train you in how to remove the cover and possibly the blower wheel. From there, have him show you how to clean the coil and the blower wheel. It isn’t hard. It is a pitn. This assumes you have duct collection. Minis have the front facing filters that are easy to clean, but you can about throw the cat through them. When you look at the wall evap for minis you see the face of the coil, but at least 40% of the coil surface runs over the top and down the back. Out of sight is not out of mind Don’t tuck the unit so high that you cannot get at it. They allow you to be within 2” of the ceiling but cleaning one of those is tough. I represented Fujitsu in the six New England States for 14 years and find them to be everything that Mitsubishi is.