They’re in the logical editor, they’re in the project logical editor, and they’re in the transformer. Why can’t they be in the input transformer?
They’re inherently useful to intuitively create more complex Boolean conditions. Without them, one is forced to tirelessly find a combination of conditionals that fit Cubase’s default sequential precedence rules.
What’s the reason behind excluding parenthesis from the input transformer? Is it to deter users from creating potentially “laggy”, condition-heavy MIDI filters? It’s a lot of checks for sure. But even then, we’re only talking 20-or-so nanoseconds of delay on a modern PC with about 10 checks. If this is the reason, I believe Cubase should leave it up to the user. I don’t know any audio hardware manufacturer that doesn’t allow someone to set their buffer size too high just for the sake of appearing faster. Nor do I see such limitations in the Cubase global MIDI filter in the Cubase preferences window.
Anyway, that’s just my speculation. Because I truly cannot think of a single reason why one would be opposed to the idea. Of course, there’s always the possibility that parentheses just weren’t even in-mind. Hopefully they are now.