Sometimes training a wrist grab escape is not all about freeing your wrist. The escape we teach first, doesn't look like most wrist escapes people have seen. However, it teaches a lot of other things: body alignment, power development, body unity, angles, body awareness, balance...
If I let the other guy get a good grip on my wrist, in a position he is strong in, then I can practice my escape slowly. By doing so, I must keep my structure correct, my balance correct, my technique correct throughout the whole process. Its a great way to work on all these other bits, even though the bad guy is unlikely, to grab and stay, while I escape.
That said, while grappling, with fully resisting opponents, I have used the principles and ideas taught, to escape many different holds. I even occasionally use very close variations of our kata versions of escapes, even though we may not be standing and static.