You should understand what is the difference between these precursors.

The difference is the "dihydrate" term, which roughly means these precursors contain different amounts of water.

Then your question can be rephrased as "what is the role of water in MoS2 growth?".

This is a big and important question that I think you need to find out yourself rather than ask around.

For your information, this issue is still controversial.

Finally, you need to optimize the growth with your own conditions since the synthesis recipe can be various system-by-system. (simple question, do you think there is a difference in using these precursors if your lab is located in a highly humid area and your system is exposed to ambient conditions?)

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There is nothing called salt 1.0 and salt 2.0 techniques, the review papers just created this term to make paper catchy.

For people who didn't read these papers, your question becomes difficult to understand so I think using this term is not helpful for you.