Very nice tank and recovery photo
Water changes are neutral to everything you mentioned and are concerned about.
If you 100% water change every morning, for example, your tank could take in more feeding without waste buildup, it would make the system better not worse. That is to illustrate the example that they are not harmful, ever, for a nano but to stave one off too long sure can be.
An example like your tank to show the theory
http://www.advancedaquarist.com/2010/4/aquarium
No aspect of a water change in a nano reef is harmful, they’re regenerative
The longest living nano reefs on the planet have done thousands of full water changes. In your case, the fish needs to swim so it might be like 80% lol
Clearly a period of no water change shows how all systems will glide
But, the oldest sources of nano reefing you can find on the Internet are getting worked with changes and sandbed attention, at least weekly typically. Below five gallons that mode becomes the dominant method one can lookup on the matter.
One reason to do them is to allow for more feeding to the corals, and because it exchanges out phosphates in solution for clean water so that your calcium carbonate structures (sand rocks) don’t directly uptake free po4 into the matrix.
It’s not that you have to or should change pace. It’s that the longest living examples have shown that changing water before problems arise is how you get a tank so old, 12+