Astound → [Need Info] Reverse DNS with static IP?

Simple question that I'm sure has been answered before:

I understand that the static IP service unblocks the normally blocked ports (25/80). But will RCN also update their reverse DNS entry to a domain of my choosing?

Trying to justify $20/month for a static IP when I can get a DDNS service for $25/year. And having a proper reverse DNS entry will go a long way towards that justification.