Aw, nevermind. I figured it out.

Hijack allows nested popups, so when the Knob is pressed AND a hijack function has been associated with the knob, then it will popup a choice between seektool and the "other" function (which for most of us is probably PopUp0, but it could be any of the other choices).

The choice doesn't pop-up when exiting seektool.

Hijack v285, shortly.

Cheers