Not sure if you're doing this already, but can a Dynadot loser...I mean user (he he) create two sets of contacts: one for WHOIS and another for their Dynadot account? Something like one set of contacts for WHOIS display that's correct, yet doesn't have "administrative privileges" to the domain name?
I ask this because your competitor Network Solutions does this. As in I can create one user with contact details merely for WHOIS, yet the one showing in WHOIS doesn't necessarily let its user gain access to the account with it.
Then there's a 2nd set or user whose contact details ONLY within the account can be used to obtain information or what-not. Just something to consider if you haven't done so yet.