I use a 38 Special j-frame BMT loader with TK Custom clips and Starling cases. Works great, no issues.
TK Custom has two different thickness clips for 38 Special cases, one for Starline and R-P cases, another for Winchester cases and others. About half of my cases are Starline and R-P cases so they get separated for the moon clip revolvers. Also, I have about 1000 new Starline cases on the shelf.
I have never seen where BMT says not to use a certain case but that does not mean it is not somewhere on their web site.
I have four different BMT loaders (J-frame rimmed, J-frame rimless, L-frame rimless, N-frame rimless) and the only issue that I have had is whether the case fits the moon clip, which is not a BMT product. 9x19 cases are extremely variable between manufactures to the point that I only use domestic cases in my moon clips.