RayQ Power up?

I'd wait until you need it, as it's likely rayq will return before that and you can find a better one.

If you really don't think you have a need for it, just wait. If you don't have a need for anything, I don't think it would be a horrible decision.

Wait, it will return within the next 3 months probably.

I'm going to take the opposite position. It's a better choice than Latios, typically speaking, so unless you have 6 Dragonite/(Salamance), boost it up. Benefits now don't lessen, other things just overtake.

I'd hold off if you don't have an immediate need. It sounds like you have the dragon front covered at the moment. If Rayquaza comes back you'll be able to find a better one, potentially shiny. How common is windy weather in your area? If common enough you can try for a boosted one to save some dust and candies.

Wait for it to come back. That's my strategy going forward: no more powering up on first run. Not only do you risk getting a better one after you've already spent resources, you risk getting a better SHINY one. I power up only one of each legendary, so that's a problem for me.

Now, I'll make an exception for Ray because I can have one powered up with Flying moves and one with Dragon moves, so I can live with that. But the others? Boo.

Do you have problems Soloing Machamp Raid Bosses right now? If you have problems Soloing Machamp, switching that one to a Double-Flying type for immediate use against Machamp would be the only reason to power it up. But even then... eh, I don't think I'd be powering it up.

This "Bring Back Legendary's!" thing that Niantic has going is really messing with long-term planning.

I wouldn’t if you’re satisfied with your dragon attackers.

Having said that, a bit of a compromise is to power it up to something less than or equal to level 30. Rare candy can be ground/grinded if needed, and if it comes back then candy can be found that way, too.

It all depends on how much you want to power up a RayQ right now.