Chainsaw Repair

My father in law has not done much sharpening of the chains on his old gas saw. I used to sharpen them for him when I was out for a visit. about a year ago, I got him to try a Stihl 2-in-1 sharpening jig (like the Pferd chainsharp CSX - sharpens the tooth and files the depth gauges at the same time). He liked it, and gets good results with it. That gas saw is just too big for him these days, and starting it was a hassle for him so he is passing along to his nephew.

So now he has purchased a Milwaukee M18 battery chainsaw. He'd like to use the same kind of sharpening system on this saw. Unfortunately, no one seems to make one for use with an 11/64" (4.5 mm) round file recommended for the .043 gauge 3/8" pitch low profile chain on this saw (I believe the chain is just the Oregon 90PX series).

My question is, would the Stihl 2-in-1 sharpener with the 5/32" round files for other styles of 3/8" low profile chain be a good choice for this, or should I convince him to learn to use one of the Oregon guides that clips on to the file or perhaps one of the Husqvarna roller guides, both of which are available in an 11/64" size.  He is not likely to take up freehand filing with just a bare round file, nor is he going to get a grinder.

If it makes a difference, he would not be doing a lot of high volume chainsaw use. He buys his firewood already split. This is just going to be occasional trimming brnches or cleaning up storm damage or trimming the occasional firewood pieces that are too big to fit in his small woodstove. Maximum production is not a concern - though he also doesn't want to waste a lot of time & energy on a crappy cutting chainsaw.

Some 3/8 low-profile chain calls for 5/32" and some calls for 11/64".  I'm not sure what the difference is, but I assume there is a slight difference in the tooth design.  Both the Milwaukee manual and the specs for the Oregon 90PX chain I use on my own Milwaukee call for a 11/64" (4.5 mm) round file.

The Oregon sharpening guide you linked is what I meant by "one of the Oregon guides that clips on to the file". They work pretty well, but he's really hoping to stick with the Stihl 2-in-1 style. That does not come in an 11/64" (4.5 mm) size. He's not a chainsaw guru, but is no dummy when it comes to using tools. He can learn to use that Oregon guide if necessary.

I suggested he try out the 5/32" Stihl 2-in-1 his nephew owns and see how he likes the results. If you are saying 5/32" works for you, I'm guessing he'll be OK with it as well.

Thanks!