Allowing the engine to cool down to allow the oil lubricating the turbo bearings to cool can greatly extend the life of a turbo. I have thermocouples installed pre and post turbo on my '02 F250 that has 150K miles on the original turbo. I leave the engine running to allow the turbo to cool if pre-turbo temperatures exceed 375F. I let the MX cool down before shutting down if it's been running hard, as the manual suggests. I might add a thermocouple pre turbo to the new tractor so that I'm not idling the engine excessively.
I know how you feel with the size difference of an MX compared to other compact tractors, but let me assure you, you'll get used to it. I had a BX for five years and when I bought the MX back in February it seemed like a monster in comparison, but after switching back and forth for different projects, I soon realized that I wasn't enjoying much about the BX any more and frankly don't miss it all now. The MX is such a capable a tractor in so many situations. The MX no longer feels huge but rather just right for what I need. It turns on a dime, it has a lot of power, it fits in relatively tight spots, it's easy to operate, it's not overly complicated and it's very easy to live with. It's kind of a modern take on an old tractor without much in the way of fancy electronics.
I wish I'd bought the cab model from the get go but thought that after 5 years of a BX I don't need to spend the extra money for a cab. I was wrong. The bigger tractor meant a rotary cutter and taking care of 30 acres or more which means DUST and chopped grass, and more dust. These rotary cutters pulverize whatever you're cutting and the dust can be brutal. I was wearing goggles and a dust mask for hours on end and getting covered in all manner of crap. Being itchy and filthy gets old fast. As winter approaches I like the idea of sitting in a cab and blowing snow rather than having the wind send a bunch of snow back in my face. When blowing snow with the BX I would always have to mess with the chute to reduce the chance of getting an ice bath. I can imagine that sitting in a warm cab and moving snow around on a sunny but brutally cold day is the bees knees. I enjoyed it on the BX (mostly) so it's only going to be better with the MX and cab.
As for stability, you can add 600lb of wheel weights to the MX which offsets the weight of the cab. You can also add a rear ballast box if you need more weight.