All the Lilygo stuff is open source and their designs are on github. I had a look at some of them and they appear to be really good (500mA 3.3v regulator on the one you linked to). Just make sure you buy from their official Aliexpress store. The clones cannot be guaranteed to be using the the same quality components.
Same goes for the LOLIN D1 mini. Buy from the official LOLIN store, not the clones. The clones are cheaper because they use inferior components and the reliability suffers.
MH-ET Live no longer seem to be selling the ESP32 mini. So avoid that one now. There are a lot of bad clones.