The previous refinements to the parsing logic were excluding --spi... value options (without an '=') from being picked up by the Config. This was not intentional, just a side effect of the focus on our primary options. So this can be considered / narrowed for backport as well.

_Originally posted by @shawkins in https://github.com/keycloak/keycloak/issues/31448#issuecomment-2243032776_