One issue with extra wide freewheels is the long unsupported drive side axle, hence all the action now is in freehubs.
The axle support bearing is on the far right end of the driver assembly..


My Touring wheel build in the 80's was around a Phil Wood freewheel hub. they are using very strong axle bearing assemblies.
rather than the 10mm threaded axle wiyh spacers that is common..

5 or 6 by 2 for 10 or 12 speed?