Reducing absorbency in primer

I’m looking to reduce the absorbancy of an acrylic primed surface (either canvas glued to board or primed Masonite) without the use of leads.

My thinking is: a thin layer of titanium white mixed with a bit of alkyd could work. Due to the alkyd it’d dry quickly, so no major risk of upper layers drynig faster.
Basically: deliberately pushing it slightly towards saturation point of oil vs pigment, but not so far that it’d be over saturated.

Does anyone know if this would cause issues? I presume that it’d all be in the exact ratios used.
I can imagine that too much would push past saturation point and get delamination issues. But would 20 or 40% be within limits, but reduce the amount of oil from upper layers that could sink lower?

Not sure if this ratio would cause a weaker film. I know that if I did this with plain oil: the oil would make for a weak film, but I’ve heard that alkyds are stronger. As it’s a ground/primer, yellowing is not an issue.