Yeah i saw those scratches on your video. Tons of info on the pros and cons ofnall the systems and info on freehand sharpening without a system. No need to rehash it all here. Search engine is yoir friend.
I use the sharpmaker to touch up on my dozen or so emersons. Not exactly free hand, but i angle my hand to match the edge sometimes use a sharpie marker to see where the stone is hitting if im having a bad day. Then angle my hand to knock off the burr ok the other side, then stropping. Since you are sharpening only 1 edge on the chisel. The sharpmaker is setup for 30 and 40 degrees but the chisel is only one edge, so i just adjust the angle i hold the knife on the 40 total or 20 degree per side side. Remember most of these knives have a microbevel so hitting the very edge at the right angle is crucial to sharp or not sharp.
Emerson has a very good section and explanation on his site on chisels and so much knowledge here to read. Take your time. Practice on cheap knives before you destroy your high dollar ones. Good luck and welcome.