I have posted many times - S04 has the size for a 300ktpa operation (max). I have measured the land area and, assuming 2km between bores, S04 can accommodate around 100 bores & require a flow rate of 25 litres per second each bore. The last S04 announced reported flow rates of up to 25 litres per second therefore S04 appear to be on track & said the bore flow rates exceeded their needs. S04 have not announced a production target but I imagine it will be 250ktpa to 300ktpa.
GPH has a smaller sized lake area, which is why the GPH production target is 75ktpa to 100ktpa. Imo, GPH will need to prove up similar flow rates of 25 litres per second, in fact, probably up to 30 litres per second.
GPH has 1/3 of the size & production potential of S04 therefore the GPH market cap really cannot exceed 1/3 of the S04 market cap (unless they find gold in those hills).