best material to size wood panel?

​Dear MITRA community,

there are many conflict info regarding what to use or even if we need to size a wood panel for oil painting.

from on line resource, some saying can use GAC100 or gloss acrylic medium to size a wood panel. 

but from GOLDEN, they revised their suggestion by saying to avoid these gloss medium in any preparation layer if intend for oil painting, so instead they recommend apply acrylic gesso directly on wood panel without a need to size first. 

however, people argue if wood is not sized/sealed first, the water content from porous acrylic gessos would keep soaked into wood and causing issues. 

i also see other people using PVA size to seal the wood instead, however from the PVA size manufacture, it is only intend to use on fabraic canvas and paper, so it is also uncertain if it is good on wood or causing any permanence issues, as well as it introduced additional foreign material that complex the structure as well. 

so i want to ask that shall the best is to apply acrylic gesso directly on wood or we need to size it first, then what will be the best material to use? 
thanks.