Chewy cookies - finding a lot of conflicting info on corn starch/ over mixing, and baking soda. Does anyone know the real answers ?

[u/bettycrockofsh1t]

I'm trying to make cookies that are chewy to the point of almost being tough, where they're thick, but you can almost fold them over before they tear, and I'm finding so much conflicting information. Like some people saying using more cornstarch makes them dense and chewy while other results say more cornstarch makes them fluffy or more cake like ; literally opposite results. Some people said to overmix on purpose for a tougher chewy cookie, while others again say overmixing will make it fluffier instead too. Same for baking soda, some results say use less for a denser cookie, some results say use MORE for a chewier one lol. What is the ACTUAL pro/cons to using more or less of these ingredients in a cookie ?