Interesting observation Dan. My basement grow area stays in the 60s during seed staring time but I have noticed that the plants do really take off when I begin to harden them off outside.

There are optimum temperatures for seed germination and also different optimum temperatures for seedling growth. 80*F is much to hot for growing tomato seedlings unless they are in full sun.

My tomatoes, seeded at 80F under lights, are going gangbusters. What makes that too hot? Sorry, but I just don't see it. Nor do others ...

https://cals.arizona.edu/pubs/garden/mg/vegetable/temperature.html

Now that's for germination, but it's well understood that tomato seedlings grow fine at 80F. Many consider 80F to be an optimal temperature for seedling growth. I could give you a list of references.