Review on MT3608 Boost Converter - Micro USB DC 2V-24V to 5V-28V 2A, Voltage Regulator, Power Supply Step Up Module 3.3V 5V 6V 9V 12V to 5V 6V 9V 12V 24V (Pack of 4) by Byron Forman

So this is actually a MT3608 based boost converter. I know this because the LM2577 is a TI part and does not come in a SOT23-6 package. I was able to kill one of them simply by testing by applying a voltage to the input and checking the output voltage (the input was much less than 20V). It stopped switching and started using electricity. I'll have to try others to see if they die too. Initially, however, there was a good stable output voltage. I will update the rating depending on the result. My first impression is that they are not very durable and need to be treated with care.