What ISP are you referring to? I have genuinely never heard of an isp that takes 24 hours to rotate your IP. Also utilizing dynamicdns is not going to incur more dns traffic? Dynamic DNS updates your dns provider from a system on your local network that your pub ip has changed then your provider will start sending traffic to the new ip. Propagation used to take a while but I haven’t experienced propagation wait times of over 10 minutes in years. This all being said dynamic DNS isn’t exactly the most elegant solution. It is just one of the simplest that I mentioned. There are significantly better options overall that completely take the requirement of a static pubip completely out of the equation and can be built using all free open source tools relatively easily.