That's a good idea...but I wonder how many people they'd have to employ just to handle the volume?

When I break-in an engine for someone, I always tell them that in the 30+ years experience that I have I've never blown up or broken in any way* an (r/c car ) engine, so if something happens, it's because of a fault in manufacturing...CYA.

* means there have been a couple of airplane engines that met the ground rather abruptly... but that was decades ago...

My typical fee is 30 bucks and I tell them that they provide the fuel, so it gets broken in on the same stuff that it's gonna be running on.

I have encountered all types...the ones who want to learn, to the ones who would have a hard time figuring out which end of a screwdriver did what!