I asked nearly this same question on health, about if professional to professional questions were on topic (Such as a high level EMT asking about strap placements on an extrication device), and I got the below response from Robert Cartaino, a SE community moderator:
That's awesome: Professionals asking professionals about the questions they have in this field.
Yes, on topic!
It would be a bit backward-thinking to exclude the questions that professionals would actually have for a site like this… because they're not "general" enough?
Think about that.
You would be excluding the interests of the the very people who will (hopefully) drive the best content of this site. You would be excluding the people who will make this site "work".
Embrace these specialized, long-tailed questions
Many sites have the problem that they strive to become soooo generic and applicable to all, that they settle into a Wikipedia-like scope where only uninspired questions that anyone could ask are allowed. And they’ve all been asked 100 times before on every other site on that subject. No thank you.
low applicability to … the general public
To throw in a bit of historical context, this sounds an awful lot like folks looking for things that are too localized. "Too localized" once describe questions involving "…very tiny geographic regions or vanishingly small periods of time", and it's an out-modded artifact we got rid of a long time ago, good riddance. Too localized is no longer a valid reason to flag or close a post.
We should not close questions because "it is too narrow and focused."
If the professionals want to use this site for their specialized interests in this field, you've gotta love it. Failing to embrace these questions with both arms would be a big mistake.
"To attract experts, you need a site where people are asking very interesting and challenging questions, not the basic questions found on every other Q&A site.
Remember, the pro sites WILL attract the enthusiasts, but not the other way around!"
— Blog Post, Your New Site: Asking the First Questions
So, to that end I've started a conversation with Dave Liepmann in the Locker Room and dropped some links to current topics. I think if we can get better questions and invite people we know in the field, I think we can revive what seems to be a lagging site.