Parameters that can't be set from server command-line (and inconsistent documentation thereof)

According to the mariadb.com reference guide to system variables, it should be possible to set the system variable check_constraint_checks via the command-line ("--check-constraint-checks=VALUE").

However, according to another page (https://mariadb.com/docs/skysql-new-release-dbaas/ref/mdb/system-variables/check_constraint_checks), this parameter cannot be set via command-line option or config file, but only via SET [GLOBAL|SESSION] at runtime:

check_constraint_checks

See also: System Variables for MariaDB Enterprise Server 10.6, in 10.5 ES, and in 10.4 ES

PARAMETERS

Command-line: Not Supported

Configuration file: Not Supported

Dynamic: Yes

Scope: Global, Session

Data Type: BOOLEAN (OFF, ON)

Product Default Value: ON

Testing (with MariaDB 10.6.12)shows that the parameter cannot be set from command-line or config-file:

[Note] InnoDB: File '/DATAPATH/db/innodb/ibtmp1' size is now 12 MB.

[Note] InnoDB: 10.6.12 started; log sequence number $SEQ; transaction id $TID

[ERROR] /ENGINEPATH/mysql/bin/mysqld: unknown variable 'check_constraint_checks=1'

Few questions...

1. How did we end up with the "SkySQL" docs correct, but the knowledge base reference is incorrect?
2. Why are some (global) system variables not settable via CLI/config-file?
   • This certainly does not simplify the end users' interface or expectations for configuring the engine.
   • Is there some internal benefit, perhaps in terms of simplifying code structure, to not allowing these variables to be set via CLI/config-file?