When it comes to evaluating the temp tower you need to check several things such as the rear of the model for cleanliness, the side of the model for overhang quality, the opposite side of the model for circular overhangs/holes and also the quality of the pin in the circle and also the quality of the bridging. You ideally want the temperature that shows no warping, drooping or under/over extrusion.
In terms of the max flow rate test you should be looking for the first layer that looks discoloured or has holes or missed filament and choose the layer that looks cleanest before the print started to deteriorate.
In terms of the flow ratio test I replied in your other thread…