Also, using this currently makes it so that the longkeypress does not work on the knob to access Hijack.

As Mark mentioned (and I neglected to mention, but had in my config.ini) you need to add:
Knob.L=Knob.L

You can configure the PopUp0 menu. Here's what mine looks like:
[hijack]
PopUp1=Tweak...
[ir_translate]
PopUp0=PopUp1,Knob,Info,Visual,VisualSeek,Shuffle,Clock,Mark
PopUp1=Artist,Album,Genre,Year,Swap

That gives you a nested tweak menu, among other goodies. The portion from the [hijack] section renames the PopUp1 menu to "Tweak..." for a nested

See the Hijack FAQ at RioCar.org for more info on how to mess with IR translations.