How hot is to hot for a manual trans six speed trans temp?

I am seeing 200 degrees when towing with 60 degree air temp. I have a buddy with the auto trans and he sees 195-200 as the normal temp for his auto.

My gauge only goes to 250, so when I am at 200f on the trans temp, I am 2/3rds to 3/4 on my gauge.

Do these six speed manual trans have heavy weight gear oil that would be damaged by these sort of temperatures or do they use the auto trans type fluids that are less sensitive to heat?

just wondering when I should shut down and cool off to avoid cooking or burning the trans fluid?

Thanks in advance