Why do they make small changes on tours as compared to Broadway?

I noticed several minor changes in dialogue on the Back to the Future tour:

1 ) When Lorraine's father finds Marty after falling out of the tree, he drags him away, and then says something about back problems and and hurting his back more

2) When marty and George are on the cusp of singing "put your mind to it" , George pauses for a moment and says something about a peculiar bird breed he notices

3: When Lorraine says "Marty, what a nice name...." George walks off stage with her and says "Yeah, it is...."

Granted, these are minor changes and inconsequential for the most part (except for #3), but why does dialogue change sometimes on tours? Production staff still tinkering with things?

In the Something Rotten licensing version that regional productions use , i've noticed there's some dialogue change there as well....Is this a matter where the creators are just still kicking things around?

hearthemsing22 said: "It doesn't change the plot or anything. They can make adjustments. They made huge changes to Mean Girls on tour and in the West End, but those didn't change any plot points. I think it gives them the opportunity to tighten things up. Get rid of things they didn't like before."

This.

Sometimes those changes are eventually incorporated into Broadway productions, future productions, or the official licensed script after they're "tried out" on tour or elsewhere. WICKED made some changes for London that are now standard.

And, sometimes a line of dialogue or a change to a song can help clarify things, especially if the physical production is smaller.