Here's another perspective. It sounds like cornering in a field is also a weakness. So, you could do the B-race and make sure you sit in and work solely on cornering in the group. If the race is as unchallenging as you say, then it would be an ideal place to get this practice because you won't be on the rivet and can focus solely on cornering. But for this to work, you would have to make sure you stay in the field.