So you are telling me an aftermarket camshaft had worn lobe after 20 hours of use? I find that difficult to believe, at best. I have put in more than one aftermarket camshaft when the compression release mechanism breaks, and have never had a comeback.
I didn't either.... Until I did!
I had an aftermarket fall in 17 hrs.
No lobes were worn but they were slipping and spinning on the splines that are supposed to hold them in place.
Lousy quality metal and likely assembly too.
I used a number of aftermarket with no issues but that was several years ago.
This one that failed was purchased May 2021 and failed Sept 18 2021.
I didn't have any issues with previous ones.
I replaced that one (again) with a Briggs with a newer longer part number and this is it's 3rd season on that Briggs replacement camshaft.
Maybe by now they have improved the aftermarket ones or maybe some are better than others although most all I have seen look identical like they were all made in same factory but who knows...
I have no faith in any of their quality and I don't have much more faith in the Briggs part as the original ones fail FAR too many times and they haven't improved the design one noticeable bit.