There's no workaround for this, it's a problem with the frontend parser. Multiple sites are affected by this, pretty much anything that uses the affected web library. However, there is also no easy solution for it so far.
I'm told that later versions of the web packer they are apparently using don't have a dependency on the affected library anymore, but that's not to say that there wouldn't be other issues, and since it's not a security or functionality issue I wouldn't be surprised if they decline to act further. No harm in asking, just keep in mind that the particular parser issue here is limited to Firefox versions before 52 (it's not a TenFourFox-specific problem), and they may simply say they don't want to support browsers of that age.
As I say, this is an issue that bites me too on other sites, but the definitive fix is complex, large and risky, and may not fix other issues this one is masking.