Not sure what exactly you mean by "tune", but if you mean run at a lesser throttle, the answer is a qualified yes (=probably ok).

Here's what you need to realize. The "50" means that you should keep the maximum current in the ESC to 50 amps for heating reasons. This is the current that you would get at wide open throttle (wot). The current we typically measure with our meters is the average current being pulled from the battery, and at wot, the average is just the same thing as the actual instantaneous current (since the current is being supplied 100% of the time).

At partial throttle, lets say 50% for an example, the current is only supplied for half the time. If you are pulling 50 amps at 50% throttle, that means you are pulling 100Amps half the time, and zero amps the other half. You may now see where we may be getting into issues! (still with me ?   )

The heating in the ESC is basically resistive, and equal to the square of the current times the ESC resistance. Note that 50A at 50% throttle gives 4 times the heating during the on period as 50A would give. Of course during the off period there is no heating. What matters is the average heating which is just (4+0)/2 =2 * the heating you would have if you were simply drawing 50 amps all the time.

So in this simple example, 50 average amps at 1/2 throttle would make twice the heat as 50 amps at full throttle.

Now the reason I think you will be ok is that you probably won't be drawing anything near 50A in actual flying--I am guessing you will be in the 20-30A range.