stainless in particular is hard to machine. It is "gummy" and also work hardens if you do not take a reasonable cut. A machine like the Smitty (or any of the Harbor Freight/Enco/whatever labeled versions) will lack rigidity to keep the tool engaged. You can do it, but it will take a very long time and be a frustrating experience . Most of the turned parts on my boat were done on my 5 hp Mori Seiki lathe (4500 lbs - a little hard to take with you on the boat). I just sold that lathe and replaced it with a 10 HP CNC lathe. I probably never used more than 2-3 hp in a cutting operation, but the rigidity makes the job far easier. Milling is even worse it terms of rigidity concerns. I started with a standard issue Bridgeport knee mill, 2 hp and 2000 lbs. It did OK on stainless if you had the time to take your time. I upgraded to a Bridgeport Interact SII CNC mill (3000 lbs, 3 hp), then to a couple of Deckel FPNC mills (the little one is 3500 lb and 4 hp). Rigidity runs all the way through the system: from holding the work, to keeping the spindle in the wanted position relative to the work, to the tool holding system. For example that Smitty probably has an MT2 spindle - not much better than a drill chuck. A Bridgeport has an R8 spindle, maybe 20 times more rigid. The Deckels have a Cat 40 spindle, maybe 10 times as rigid as the R8.

Those little Chinese combo mills are not highly considered by most machinists. Right now, with the industry in shambles, you can buy real American made used machine tools for less than scrap value. If you have the space for them, you will be far more satisfied with the performance. However if miniaturization is required, take a look at the Wabeco tools. They are not cheap, but you get what you pay for. If you want to try the Smitty, find a used one (they are everywhere), then if it doesn't do what you expected you can sell it and not be out very much.