Delamination?

Square about 18inches has delaminated by kitchen sink is there any reason I should not use the following method.

Drill 1/2inch holes around the dipped floor
Raise the dip by screwing a batten across it to draw it up. Then fill with builders foam pumping in to each of the 1/2 inch holes then fill up the holes with 1/2 inch dowel.
Alternate cut out the dipped area flooring board level out the dip in the insulation and glue new 3mm boarding fill any gaps on edge sand down job done solid floor again. Have already got the leveller fluid, board and adhesive from a previous un related project.
comments please.
Many thanks in anticipation