[thincom2000]

It's not going to really screw with future upgrades. The changes the hack makes will be overwritten when you upgrade to a newer version of vBulletin, and the modifications made have no known negative side-effects on vBulletin functionality. All we're doing is adding a single line of code here and there, not removing anything at all. <-- I believe that answers your question.

If your issue is not wanting to make file edits again when you upgrade your vBulletin software, read on. Most vBulletin updates are small, and you don't have to overwrite every file every time.

Many hacks may require you to make file edits. The upside of the Product Management system is that after a forum upgrade you can check your products and see which have file edits you may need to do again.

The edit for this isn't a big one, and with a quick Edit -> Find in your FTP client, it really shouldn't take too long to make the changes. The template edits required take into account the case of an upgrade where the new hook is overwritten from your edits, so that your navbits won't be mysteriously broken. Instead, the hack will just be non-functional until you re-edit your files.