Yes - Birmingham is worthwhile if you have time. If you are doing the ring anti-clock and if you find you have a day available to add to your trip when you get to that point, then you could replace, say, the 1 day jump from
Bluebell Cider House > Alvechurch
with a 2 day hop such as
Bluebell Cider House > Birmingham Centre > Alvechurch
This avoids any of those less than desirable overnight moorings.
In any event, there are notably zero locks in this part of the journey - an ideal preparation for Tardebigge!