My understanding is that government departments have been managing with accrual-based information since 2001 and are already comfortable with it. That major transition was relatively smooth.
The estimates are a different piece of managing your responsibilities, and it's your authority to do things; essentially in this case the authority to use public funds, and under the accrual basis the authority to use public resources broader than cash. It's just a different way of looking at your appropriation. But since federal government managers are already using the accrual basis for managing the departments and agencies, they're already familiar with it, so I don't think there's a large risk there. It's just the understanding of what an appropriation under an accrual basis means, how to understand it, and how that trickles down to how they link it to outcomes.