The HTML file I used has %PLACEHOLDER_SENDFEED% and gets the text replaced with the details from the EEPROM before serving the page.
This was testing using the ESPAsyncWebServer processor.
Served several different files as static files but sometimes doing all those files at once causes the ESP32 to lockup and reboot. Still looking into it.
Only seems to happen on initial loads. Once the files are cached, no problems.
Setup a subscription feed to retrieve the message coming from the other device.
All files are served, tried adding a websocket connection to send the retrieved subscribe even to the open websocket. Worked!