A misinterpretation on my part, it seems.
Consider: First gear, steep, rocky, way under power band, wot. And you asked about the pilot jet.
I took that to mean a TRANSITION to WOT, or the effect when you give it a quick flick TO wide open throttle.
I can't imagine your situation. If you're WOT in first gear on a steep rocky section, you should be in 2nd gear already (maybe you'd already been there and the bike couldn't PULL 2nd gear?). You'd have to be getting either wheel-spin like crazy or in a couple milliseconds you'd be snapping the rear fender off after you had looped it.
If you're WOT in first gear and the bike is NOT rev'd to it's maximum, I don't know why you'd be HOLDING it that way. Clutch fanning would have already been happening.
If it's NOT a transiton, but HOLDING it wide open, then you are correct. Pilot jet is out of the picture at that point. It's going to be the main jet that is the fuel metering device.