BriskBard, CEF4Delphi, WebView4Delphi, WebUI4Delphi and WebUI4CSharp

GlobalCEFApp.EnableFeatures and GlobalCEFApp.DisableFeatures can be used to enable or disable these features https://chromium.googlesource.com/chrom ... eatures.cc
GlobalCEFApp.EnableBlinkFeatures and GlobalCEFApp.DisableBlinkFeatures can be used to enable or disable these features https://cs.chromium.org/chromium/src/th ... ures.json5

How can I find out the full list of what is supported and whether the status is enabled or not?

Experimentally, for one site, I was helped by the solution EnableBlinkFeatures:= 'SensorExtraClasses'; But how to find out what is not working yet\disabled, and what might not hurt to disable?

I'm sorry but I still have to read many Chromium documents and I can only suggest you read the code comments in the links you posted.

Here you have some more information :
https://chromium.googlesource.com/chrom ... eatures.md
https://groups.google.com/a/chromium.or ... 2LkfEslTAJ

I had more in mind how to find out default settings?
Reading something is one thing, but checking it out is another.
Can who site, online verification knows, certainly there is, where it seems show add-ons are enabled or disabled.