Hi Anton,
Thanks for posting your questions.
Your inquiry about a top-level convenience parameter is something that was discussed during development of the standard. An alias mechanism allowing multiple (synonymous) names for a parameter was considered. However, this is non-essential so it was decided to defer it in the interest of simplicity for the initial release. You are correct, the workaround is to create a separate parameter and synchronize them.
It is possible to hide parameters as you’ve expressed. The mechanism for doing so is not standardized but example 14 demonstrat