Here's how this could work...
While having a limited AM/FM signal gives it prestige, they need to promote an app, website, and streaming platforms at the forefront, with the signals secondary.
LGBTQ businesses heavily advertise and promote themselves within the community. Just open a copy of Bay Windows, Boston Spirit, or the Rainbow Times. They are full of businesses advertising. Use those outlets and place full page ads promoting Radio Q. while meeting and introducing themselves to every LGBTQ owned/friendly business to gather support and advertisers. And of course, be there at community events and gatherings.
Programming needs to offer as much local content as possible.A music format similar to KGAY should be considered, and hopefully not CCM. Otherwise the religious music and programs will not go over well within the LGBTQ community. In fact, this would only alienate your audience, and cause controversy. I can only imagine the backlash as a result.
Of course, this requires some money, time involved, and the networking required. And hopefully they will have at least a small staff to help get this off the ground. I think having the money to back this up will be the deciding factor as far as success.