I have many domains and I have a dynamic IP in the past which changes once in a while, and when it changes, I have to go into the domain registrar and update the new IP for my home web server. The Static IP would resolve solved this but it’s not cost effective your websites domain isn’t that popular, however it is effective if you have contents sites that get lots of traffics then definitely get static IP for hosting your websites.
With a lot of domains to maintain, especially with multiple domains registrars and multiple web servers, on top of that with a dynamic IP could be a waste of time when the IP changes. To help monitor and checks, to perform your task of updating the IP correctly appropriately I recommend this little software call “DNSDataView”, it can do NSLOOKUP based on a list of domains maybe up to 100 or more but it could take times if you have a big list. It will perform nslookup and provide you detail data which you can export to excel or text to do further analysis. Very useful for me to speed up my work.