I just realized that my ESTJ sister is incredibly stubborn, but I know how to crack her code/shell to make her see the light.
For me, ESTPs can easily crack my unwavering stance, because they have a knack for finding a better way of doing what I intended to do. And INFPs -- they always patiently remind me to add the "human" factor into my decisions.
"I cannot expect even my own art to provide all of the answers -- only to hope it keeps asking the right questions." -- Grace Hartigan
Well when you put it like that, it's usually the secondary function that has its limits. Such as "No this is what this is used for, you can't do it like this. I'm not inclined to do it that way," like how INxJs might insist that things go according to the likely plan, and not all of the alternatives they can think up. They're still learning how to cope with the world and protecting their secondary function because its kind of a weakness compared to the primary function. I see the primary function in someone as more evident to their lifestyle, as though one is oblivious to how they think, rather than making a conscious decision to enforce one's ideas to fit into their lifestyle. An S function for instance, fits better in the P lifestyle than the J lifestyle. So ISFJ might have a hard time trying to adapt and acquiesce to sudden changes in plan even though they want to in the long run. I see this generally differently for ESFJs, even though they are generally polite about it.
xSFJs are pretty stubborn. it's hard to prove a point or worse teach them something.
so they just refuse to understand it.
In my experience SFJs will be pretty quick to acquiesce on the surface, but they never actually change their opinion, and when you aren't looking they continue on merrily as though the exchange never happened.
"There's no need to be embarrassed about it, Mr. Spock. It happens to the birds and the bees!"