- Use blind accessibility tools with your website. If you're on iOS/macOS enable VoiceOver, figure out how it works, close your eyes and use your website. - Disable JavaScript and use your website. This may not be relevant for web apps, but regular websites should work normally. - Try to use your website with only the keyboard. - Try to use your website with extreme zoom levels and font size overrides. - Monitor your…
He does suggest all the things you've mentioned above, and it's good advice.
However one thing he also says is: don't assume that low-vision is the only type of disability. You also need to build software for people who are: deaf, have slow motor skills (e.g. avoid putting strict time limits on user actions, or making things jump around on the screen too much while people are trying to hit a target), lack fine motor skills (e.g. don't make a target too small), etc.