I can't imagine that having a smart water meter will make any difference whatsoever to your water usage and bills, given that you already have a non-smart meter, take readings and so are paying for your actual usage.
As long as you are happy to keep sending them readings, it doesn't seem worth the hassle of having it changed. I certainly wouldn't bother unless they were offering an incentive.
What a difference a day makes 😢😢
