Phosphorus deficiency’s are rarely because there’s not enough phosphorus there for the plant. 9/10 if you’ve got a phos def you have something going wrong in your environment, media or nutrient causing it to be locked out. Throwing more phos in there is just adding fuel to the fire. It’s why I got on the calcium foliar train, calcium is hard for the plant to absorb through the root zone in sufficient quantities and bonds with phosphorus in the media/nutrient to form dicalcium phosphate which can’t be uptaken by the plant and therefore locks out both the phos and cal it contains.
Product like mammoth p (which I don’t personally use) are good because they help break down this dical phos and make the phos more mobile and easier for the plant to uptake