Howdy
I don't think you will find any reliable published data for loading Smokeless into brass shotshells.
Smokeless powder is much less forgiving in a shotshell than Black Powder is. Basically, you cannot put enough Black Powder into a gun in good shape to hurt it. That is not the case with Smokeless. The makers of Smokeless Powders go through great effort developing specific recipes for various combinations of hulls, primers, powder, wad, and shot. They run all these loads through pressure barrels to verify the pressures are within safe limits. The nature of Smokeless shotshell reloading is such that randomly substituting any one component in a specific recipe can have unknown effects on pressure.
Frankly, I don't think the market for brass shotshells is big enough that the powder manufacturers want to bother coming up with recipes for brass shotshells. Without being tested in pressure barrels, I would be very leery of any data that I happened to come across. I would not trust anything that the powder manufacturers themselves had not actually tested in a pressure barrel, and I do not think they are interested in developing loads for Smokeless in brass shotshells.