No, they aren't in error, run 50-1 in a Saito FG and you will soon lose it. It is a Glow motor converted to gas, and it is a 4 stroke to boot. Never think you can run 2 stroke fuel in a 4 stroke and think it will last. Even at 16-1 ratio, there is very little oil in the crank, and the exhaust leaves very little residue.
Follow the instructions in the manual to the letter and the engine will last a long time. I am very careful not to get the 2 stoke fuel mixed up with the Saito fuel, don't want to damage the engine.
When I broke in the FG-11 at 20-1 there was very little coming out the crank case vent, and that had me concerned so I went 16-1 and saw some oil, and that made me feel better. I use a scavenge pipe attached to the muffler to suck the residue out and away from the plane so all I need to clean up after a few hours flight is a small bit on the landing gear.