The key point to these is that one needs to directly run the Kernel .EXE, instead of the WIN.COM command, and have the correct directory contents.
So for 2.x, one needs to have the following modules available (with these names):
You then remove WIN200.BIN and WIN200.OVL, replacing the former with an empty file.
For Windows 1.x this is a bit more difficult, as the normal Kernel does not seem to contain the code for the Slow Boot mode, and one has to use a debug Kernel, which would be found in the SDK.
Having found that, you'll note that there is no need for an OEMFONTS.FON file, but there is a difference with the necessary stub aggregate file.
You instead remove WIN100.BIN and WIN100.OVL, replacing the latter with an empty file.
In theory you also need to have a renamed grabber file (DISPLAY.GRB) present, but I don't recall needing that. It is probably only required if one starts a DOS window.