The salt content of the oceans should be connected to the amount of soluble minerals and ions, that the atmospheric and surface water of the earth, dissolved, forming the oceans. One of the most common crustal minerals is Felspar, which contains sodium and potassium common to the oceans. However, as Felspar, these cations are tied up in the mineral matrix and are not very soluble in surface water; granite.
The question becomes how did the water solubilize these locked up minerals to get the current ocean concentrations? One answer is hydrothermal water, or water above its critical point; very high pressure and temperature. At supercritical conditions, water becomes a dense fluid, that is neither gas nor a liquid, but is as dense as a liquid, but acts more like a gas. This phase of water is very aggressive to most minerals and could break down felspar, silicates; beach sand, and other minerals. This suggests supercritical mantle water, laden with dissolved minerals, working its way to the surface with volcanic activity, was feeding the oceans, while dissolving the crust.
The Bible says that at one time water used to rise as a mist from the land.
Genesis 2:6-8 English Standard Version 2016 (ESV)and a mist was going up from the land and was watering the whole face of the ground.
This is reasonable, since the surface water only scenario would have to explain how all the soluble minerals somehow ended up on the surface of the earth, making it easier to dissolve. There is more flexibility and less assumptions, if we allow the water to become supercritical to dissolve out causal minerals, and bring these to the surface, with the supercritical water.
The mist rises to the surface and then into the atmosphere, cooling as torrential rains, from the upper atmosphere. These would be the most intense storms in hisotry. The cooling rains would then cools the bubbling and steamy oceans. This caused the super heated oceans to cool and precipitate minerals, until the finally, the modern oceans appear ripe for life to appear. The Miller experiment simulation may be appropriate with this oceans forming scenario and the very active atmosphere that would include dissolved gases.
One wild card is the moon. If we assume the earth and moon were both forming and only the earth had water for amplified cooling, the hot and molten moon would have inhibited cooling, as a revolved around the earth; moving hot zone. This might tell as about the cooling patterns and the forming ocean currents.