Does Dyn (at any subscription level) have a quota or restriction on the number of DNS records that can be added to a single zone?
In comparison, a competitor's product has a limit of 1000 records that is increased to 3500 for higher tiers.
I would like to ask if there are similar restrictions for Dyn's managed DNS services.
Yes, there are quotas. See https://dyn.com/dns/pricing/