I do not believe there is a Brother ran forum. I did a lot of my research on these forums as well as Screenprintinguniversity's Brother forum before I purchased one.
Inkjet Garment Printing - Screen Printing University • Index page
(Click on Digital Garment Printers, then Brother GT541). Of course, if you can't find the answer to any of your questions, feel free to ask and hopefully someone will be able to help!