I tried asking this as a feature request over on Github, but somebody misread my ticket, gave me completely the wrong answer, closed it without a second thought and ignored any further response.
So, the current documentation gives the following example for enabling additional output formats in Hugo:
[outputs] home = ['HTML', 'AMP', 'RSS'] page = ['HTML']
This kind of implies that ‘HTML’ needs to be explicitly there to enable export to HTML, else it’s disabled, right? Unfortunately this doesn’t seem to be the case and I could leave that out entirely like so:
[outputs] home = ['AMP', 'RSS'] page = 
…and Hugo will still export everything to HTML, whether I want it to or not.
I don’t want to disable the page kinds outright, I just want to be able to disable outputs to their default formats while still being able to enable other formats. I’ve got my reasons, I swear.