I did not notice the wording mistake I apologize for this but I must ask what tanks with Caridinia have you seen with black live rock? What kind of caridinia?
Dude come-on.
I am not going to do the heavy lifting here for you.
There are literally thousands of shrimp keeping (maybe tens of thousands) aquarists using lava rock in their aquariums.
Just do a simple Pinterest search (as one source).
There are some rock star planted tank aquascapers (with a global following) who use nothing, but lava rock in their hardscapes.
Reason being? They claim that the lava stone influences their parameters the least in terms of stone inertness which directly contradicts some opinions here.
Like I said from the beginning YMMV.