WPS variable selection

Dear experts pls clarify my doubts,
As per asme sec 9 position is not an essential variable for WPS .
Let consider I have a pqr qualified in 1G position as per code I can use that WPS for Vertical position welding but by doing so how can I choose the parameters correctly.
The current range required for root run in flat position will it give sufficient penetration and fusion in vertical or overhead position?
How can we select it?

ASME IX QW 409 Electrical Characteristics.
Take SMAW for example (QW 253)
QW 409.1 (Increase in Heat Input) is only an Essential Variable when Impact Testing is required.
QW 409.4 (Change in Current or Polarity) - again only Essential if Impact Testing is required.
QW 409.8 (Change in ampperage and voltage range) is a non-essential variable

Welds not subject to impact testing and corrosion resistant weld overlays are not subject to volt/amp limitations in the PQR per ASME IX


Thanks and that’s clear for me.
My question is how can we choose the right current for a 3G position from a flat position.
Does the welder himself adjust and find out a good value or do the Inspector want to specify the values if so from where he get the values ?

Please find out standard welding procedure qualification: