If you want to ram 4mm x 16mm screws into a hole designed for 8/32" x 1/2" then have at it. In mm a 4mm screw is actually 3.8-3.9mm, depending on brand. An 8/32 is 4.04 +/- depending on brand. May not seem like a lot until you hold the screws side by side. It is NOT the correct way to build a car.
The chassis has 20 8/32 holes in it, not 12.
It also has 20-22 smaller 5/64 sized holes in it. All of those are countersunk for metric hardware also.
Losi would not send out a product like this as you have stated.
This is not a cosmetic issue in any way. If we use 4mm fasteners then the plastic Losi parts are damaged for future use, and they do strip using the holes. (I started assembly per your recommendations, the third one stripped.) Besides the fact that we now have a car with metric and standard fasteners.
If we use the correct hardware for the car we are working on, the heads stick out of the chassis up to 1/16 of an inch and the strength of the fasteners is compromised due to the tapers being incorrect.
Lots of people do lots of things that "work". That doesn't make it right. unfortunately in this hobby, many enthusiasts don't know any better, so when a company tells them to do something to cover their own mistake, the people believe it. People don't know better to stand up for themselves. Or they know that complaining will get them nowhere, as this last post has proven.
If Tekno truly cared about their customers, they would send out 82 degree countersinks wrapped in a $20 bill to cover our time to fix a product that never should have been sold to begin with.