I mostly set it up for making keg sized batches of cold filtered coffee, at 3kg of coffee a batch (commercial experiment)
Personally I share the opinion that for brewing solids should be kept out of packaging. You don't need to dry hop bottles so you don't need to dry hop kegs, that's what unitanks/bright-tanks... are for.
Considering the price of the filters at <$5, and that they slip off the dip tube (which leaves a fair sized hole in the top, without the grommet I could get a test tube brush in there no worries) if you need to do more than just back wash them to get them clean, meh - wouldn't bother over engineering them.
I'm not in the market for any more, cant tell how many you would expect to sell, I'd probably just get in touch with whoever is making them and grab a few to have a play with first up.
Could be a useful product but I wouldn't invest a bomb in R&D.
Mark