There are often problems with betas that are resolved by the time the public release happens, and issues change even between beta versions. In this case it’s a very basic browser height calculation that’s broken and avoiding the problem is not at all trivial.
I don’t think it’s odd for us to put the onus on Apple to fix this, it’s a very sloppy issue that will impact thousands of sites beyond Discourse, and even occurs in Apple’s own support forums.