FE/FC FC350 Suspension tuning & Sag

Hi guys,
I'm in need of some recommendations from expertise's
I did my static and full geared(stand up) sag, Im at 103mm now
first question is: standing up or seating down for measuring?
most you tubers say up but a few say seating down (service manual picture shows on the seating position)

The other advise Im looking for is:
I just did the revalve(motocross) on my weight springs specifications, etc... with a local suspension guy, went for a 1st ride test and all was well except in a couple of clean exiting jumps...rear wheel was kicking side ways…I'm thinking it could be something simple with reb & Comp tuning…any advise will be great,

Thank you in advance.

I've always done seated.
I'd also say you need a bit more race sag than 103. 105-112 is the range I see recommended and I'm at 108 for my personal preference.

For the rest, experiment (might try less HS comp, and/or slower rebound on the shock) , or talk to your tuner guy for input.

Thank you Sir for your input…I will try more open sag