Orlando seems to be a weird case. They will only support a team if it's good. That's more of the reason why the Rage and Apollos drew well but the Guardians didn't. That, and the totally haphazard way the Guardians brand was forced upon that team (I mean, why not bring back the Rage and give some credibility?). Orlando was just badly handled from the start and would've been far better if they had gone with a more market-appropriate brand. You'd want to be in Florida—it's a business-friendly state with a lot of people with money who are into football—but which city would be a challenge. I know the Stars Football League made a go of it in Fort Lauderdale, which would be interesting. But other than that, it's Tampa (which the Vipers didn't do great), Orlando (see above), or maybe Jacksonville (now that would be interesting, given it has literally no other major sporting competition and would be a great legacy USFL market).
As for Seattle... I think it's complicated. They had poor scheduling, bad weather, and then the NHL released the Kraken in the interim. What was a great market in 2020 suddenly looks less certain in 2023 and 2024. I'm thinking Tacoma. Like Arlington, Oakland, or New Jersey, you could build that unique metro identity while still tapping into that metro, plus they have two ideal sized (if somewhat dated) venues in the Stadium Bowl and Tacoma Dome (I'd suggest the latter). I think a Tacoma Sea Dragons would be a big hit if done right. BUT... I'd like to see them find a way to make California work and establish a West Coast hub to keep travel expenses down.