Do I need to rescind POA?

I had DAV represent me on my previous claim. Ultimately, while I was successfully granted and the majority of my claim, I was not satisfied with DAV for reasons that do not matter here. Now, I just filed new claims with my county VSO. These new claims are in step 2.

Last night, I woke up and realized how I could proceed and file a supplemental claim for the 2 conditions that were denied on the previous claim with DAV. I did not think I was going to touch those supplementals just yet or at least until the new claims were decided, but I am now confident moving forward.

Can I have to separate claims, being represented by two different entities at the same time or will I need pull back the POA from the DAV or the county VSO?