Let's Control It

I tried now the core 2.4.0-RC2 for a while and here is my experience: The numbers and letters on the web-interface can be removed before compiling. No problem for that. But: It is messing sometimes the rules and formula!!! If you are only upgrading and change nothing, it works stable so far....

Feel free to add yours.

Removing the numbers from the webinterface comes with a downside. They are there for a reason.
If you remove them, you break the chunking mechanism of the website output. That mechanism allows the webserver to stream out the webpage in parts without prior knowledge of the entire size. It just announces the size of the current chunk.
The 2.3.0 core does no inherent chunking. Remove the numbers and webpage generation with 2.3.0 core does not work with Win7 Browsers any more. (tested Chrome and FF)

It seems to work with the 2.4.0 core though as they do (or try to do) chunking inherently in the server. At least it works on Windows and Android.

Beware: It does not work (and potentially crash your ESP) if you access webpages via VPN. Don't know why but with VPN on I get a chunking error in the browser, there is no page diplayed and the free memory of the esp drops to 10k. It stays that low for several hous and than returns to normal 20k. Apparently without crashing completely. At least the uptime continues to rise. The web interface on the other hand remains inaccessible.

Cant you make the numbers "invisible" using HTML?

I think that cannot be fixed in html. That would just be a workaround anyway.

The chunking issue is possibly related to an open issue in the 2.4.0 core:
https://github.com/esp8266/Arduino/issues/3225

I look into it.

Here is a fix for the letters / numbers / vpn issue:

viewtopic.php?f=6&t=3673

There is also sth wrong with entering %systemvariables% in the oled display webform but I am on it. Result will be posted in the thread linked above.