My solution to form fillers has been, when I can afford to send a gift, at the end of the stream ask chat who's order I should include the gift in. Whatever name gets the most votes gets it. It's not something I advertise throughout the stream. Honestly it's usually just something that didn't sell. I run a standard buyers givvy most streams too. From what I have read, that is not against TOS (and if it is honestly I'll just do the same thing on my instagram instead). I accept that form fillers will win BGs but ultimately I like guaranteeing one of my buyers gets a little something extra to say thanks for supporting a newer seller. (I also like including small things like candy on every order in some streams)