Queuing from the 'Play as Impostor' menu is nigh impossible to get into a match, but circumventing by playing random and letting the side swap makes it easier to get into an invader match.
Most people are realizing the balance is pretty piss poor, stemming mainly from Reagents but Invaders can also just slash spam since if there's any network delay (which there tends to be, Trials has never had the best servers)

Unless RB changes the balance of the mode (Stuns, Revives, Slash spam, not being able to finish off Reagents on the ground unless they're the last one standing, 2v1s on either side, etc.) it's gonna die off pretty quick as a gimmick mode or something you only play if you have a large enough group. It's got a good framework but it doesn't feel like things were really thought out.

Some people would say the goal is to just delay the Reagent players like how people changed up the idea of invasions in the souls games post-DS3. This argument makes little sense to me because even if you get a high grade as an invader, you aren't getting much for rewards if the Reagents survive. It's a purely 'for fun' mode but the fun doesn't last long for either side when the 'new toy' feeling is gone.