This seems really sad. But I guess it depends what the goal is. If you want to integrate onion purely on a DNS resolver and network interface level and then use a stock browser for accessing the services, yes, you'd need that.

(Then you'll also have to fight with the stock browser for using your special DNS resolver, not leaking info to Google, Cloudflare or whoever else, etc etc, tho)

But don't most people use custom browsers with built-in support for onion anyway? If that's the case, the easiest solution would seem to just declare .onion a "secure origin" like localhost and patch the browser accordingly.