As I wrote before, and will again until it penetrates; changing the thermostat to lower values does not equate to good outcomes. These discussions are always about how lowering the engine temperature achieves more HP through...what...exactly? Please give me some logical, reasonable, thermodynamics based answer!
This stuff is what I post about. 20th century hot-rodding "lore" that doesn't make any sense in a modern GDI engine. None of the thermostatic tampering or even playing with ECT in a tuner will impact IATs with composite intakes, etc. The engine temperatures are optimized for piston wall clearance, oil temps, and fuel evap points. All you're going to do is upset those things resulting in higher wear factors on the cylinders, plugs and higher short-term and long-term ECU correction factors. It's not going to make any difference in HP- it's only going to make your engine less efficient and reliable.