So Lawrence was the patch manager god here at solarwinds before he died and I almost always take his advice as gospel when it comes to wsus and PM. When he says drivers are a bad idea via wsus i just dont even try it. The general consensus on the internet also agrees with him that drivers via wsus is just a bad idea. I know that doesnt answer your question but it may help save some time even trying it.
+5 ... Drivers via WSUS are a PITA on so many levels.... in addition to the headaches of even finding the right driver (if available) to approve, you also have the practicality that the drivers in MU/WSUS are never the manufacturer's latest drivers. (To get into MU/WSUS, a driver must pass Microsoft WHC testing.)
And, beyond all of that, there's a litany of recent history where the additional size of the updates table caused by those 30000+ drivers now in the MU/WSUS catalog can have significant performance impacts on the operation of the WSUS server, and in some cases are believed to be the root cause of ongoing Timeout issues trying to perform update queries and run reports from the console.