I agree with everything folks have been telling you. A cat needs whatever amount of insulin it needs and there is no indication that those highs are from bouncing. You keep focusing on those yellows when on 3.5u but in fact 2 of three yellow readings were taken with a human meter which means they would typically be lower and therefore are perhaps skewing your view of what is happening. Yoshi is not dropping much and more insulin is needed. Hopefully the dental procedure will alleviate the inflammation that can so often be the cause of those higher BGs but until then he needs more insulin.