Hi Asif and all,
You might be interested to know that I teach a workplace innovation course at Royal Roads in which we draw from both human-centred design methods and Liberating Structures, and I've found a lot of parallels between framing a design question in human-centred design and crafting an LS invitation.
It might be useful for you to look at the HCD method called Frame a Design Challenge to think about this more. See point 3:
"Another common pitfall when scoping a design challenge is going either too narrow or too broad. A narrowly scoped challenge won’t offer enough room to explore creative solutions. And a broadly scoped challenge won’t give you any idea where to start."
Same thing with an invitation in LS, I think! I, too, am looking to see how to continue choosing the right questions...a lifelong journey in facilitation in general! ;-)