ThunderSlug

I have lately been noticing a slight stuttering/hesitation when shifting into second gear. When it shifts into second, it doesn't feel like it's fully in gear until I step on the gas a bit more then it feels locked in. The rear main seal was recently replaced at a local Indy shop which should have filled everything to spec. I bought an aftermarket dipstick to check fluid myself; link below. I ran the car for 25 minutes on a hot day to get it fully to operating temp and checked the level. After several checks, the level was a solid 1/2" above the full mark for 80C. Is it possible that I was pushing the dipstick in too far? (I had to wiggle it a bit for it to feel like it was all the way down). Or if the trans fluid was hotter than 80C, would it expand to the point where it read that much higher? (It was very hot). Or do you think it's simply too full? I'll check the level with the engine cold tomorrow and see if it still shows overfilled.