[2.0.12] p0_s for liquids returns 40 for formulas

[Criperum]

1. make a parametrized BP and use stack size variable in parameter formulas
2. Place BP choosing any liquid as actual value

Result:
Stack size is 40
Expected result:
Zero may be or some way to handle it inside formula itself

[Criperum]

More likely any formulas with p0_s of liquids resolve to 40