Nice post, and good job!
For those thinking about doing something similar, I’m also doing whole house monitoring.
I’m using the PZEM-016, which has no display but seems otherwise very similar. Since I have a split phase system and I wanted to monitor both legs, I didn’t want to have two ESPs flashed with tasmota running next to each other, so I’m using the USR-W610 to connect to the two modbus outputs of the PZEMs and convert them to modbus TCP/IP and connect it to my WiFi. From there I use the Home-Assistant Modbus TCP component to read the values, and some template sensors to combine them.