cli switch to ignore a certain extension

Description

when running php on the CLI its sometimes usefull to use the default config, but ignore only certain extensions.
(e.g. because these extension bring a perf hit when loaded, like blackfire or xdebug)

atm its quite some work to invoke PHP via cli, with all the default settings but just a single extension not loaded.
see e.g. composer/xdebug-handler which needs a lot of code to just make the use-case work for xdebug alone. I would need a similar thing for blackfire (and maybe another one for tideways).

I manually tried using php -n -dextension= ..<all loaded extensions here except xdebug> but this does not work.
(I think I would need to replicate most of the logic in composer/xdebug-handler)

would this problem be more easily solved with a new cli option at php-src level, which would allow to use the default but disable certain given extensions?

The issue names no files or tests; start by tracing PHP CLI option handling and the behavior of -n with -dextension. Confirm how the default configuration could be preserved while excluding named extensions, then define the option’s scope and completion criteria with the maintainers.