Disabling the alt-text popup or forced uncapitalization does not affect "normal" accessibility. The alt-text pop-up is custom made in replacement of using the title attribute, and forced uncapitalization is done using CSS's text-transform.
Dark/Light mode toggling will be available whenever I figure out how to do so entirely just using CSS or until I decide to remake this with JavaScript.
Saving these settings will also be available whenever I decide to remake this using/attach some JavaScript to this instead.