An elite doesn't have to have exactly x2 hp (the templates prove that), but similarly you can't just call a monster elite because it takes half damage from some powers and extra damage from others.
Like, that elite phane that is insubstantial, has double hp, and weakens (making you do half damage)? Well, double hp is elite, so insubstantial (takes half damage all the time, not just the swarms part of the time) makes him, what, Solo... and weakens for... what's a double Solo? Let's go for 'Singularity'.
That's completely absurd. You don't fix problems with the stats of something by lying (let's pretend it's elite), you actually fix its stats.
This isn't 3e where you follow a formula to generate all the stats, CR increases (honest, a half-fiend 20HD dinosaur is CR 9... the blasphemy that autokilled, no save, the entire party not-withstanding... right?)