Apparently this bug only occurs if the node value is of a text node that is not wrapped in a CDATA section. So this only applied to some responses in VaultWiki 4 under XenForo, but these are now wrapped in CDATA sections. Either way, all references to firstChild.nodeValue are now wrapped, in case behavior changes due to a fix, or CDATA doesn't save it in other browsers with the issue: Opera has a 32KB limit and Safari has a 64KB limit, albeit better than Firefox's 4KB but attainable nonetheless, and I haven't read any tests confirming or denying the CDATA workaround for these other browsers.