Interwar stockpiling was already extensive

Did limited interwar funds mean Britain could not stockpile useful naval material?

No; a tremendous amount was already stored, so the counterfactual asks how that real practice could have been directed more deliberately.

Britain retained a tremendous quantity of material from the First World War and added more during the interwar period. Stockpiling was already an established logistics practice. The counterfactual changes the scale and selection of those reserves. A more deliberate programme could preserve the particular weapons, components, and production bottlenecks that later shortages made especially valuable.