I wonder how long he has been instructing. He may be bored with slow flight and if this is the case, your not getting any benefit from it. I am assuming your on a buddy box? If he has given you control on each channel when you "take it" simply roll the throttle off to where you deem comfortable.

When your flying it is "your" bird. When the instructor is flying it is "his" bird.

I would let him know you want to explore "slow flight" and see what his reaction is. If he is hesitant or ignores you. It is time to get a new instructor.

I have been flying RC since 1984 and I still dont like flying at full throttle all the time. It is too much work. I like doing aerobatics etc but just turning the pattern at full throttle is no fun at all.

You need to learn slow flight so you can recognize what the airplane is doing and how it reacts to control input and this will get you ready for the landing as well.

Wish you well.

Glenn Williams