as the installer is basically maintained by 3 people of the community, according the contributors of the module repo, its possibly the best to address it over there (like you already did).
Also have not yet seen that it got picked up widely by others hacking on it.
I personally dont like the clamares installer, so I not want to contribute to the calamares module, as it gives a highly misleading impression that people will have a great experience using NixOS with graphical tools, which is not the case on my personal opinion.
At that is what is left as impression from my discord server experience from new people asking why the installer left them with a system they can not handle (not knowing where to start, what to edit, etc pp), which they might have come along when having to look into the manual for a getting the system to install.
Despite my personal opinion its of course everyone’s free will to do whatever they want and invest time in topic they like (so not i do explicitly not try to blame that there is a calamares module and that there are some people thinking that it provides a benefit for others).