I know there are workarounds.
And the workarounds are how i currently handle these situations.
However I think these commands would be simple to add into mIRC and think that there could be many practical script uses for these commands to make things easier / simpler / faster / better / more convenient.
For example if we didn't have /set, /unset, and %variables, we could use /writeini, and $readini (variables.ini).
However Global Variables are easier / simpler / faster / better / more convenient.
The fact that i think these would be simple to implement with little effort is the only reason i suggest them. Otherwise I wouldn't bother and would suggest everyone use workarounds.