Powering Up Low IV Shiny Dragonite

Honestly, I don’t think 62% is all that bad for what it’s worth. Exclusive event Pokémon with an exclusive move that’s comparable to its best. I’d do it gradually with all that dust. Maybe take it to 25, 30 for now if you’re skeptical?

I would say no.

Sure, it might be fun to own a high level shiny Dragonite with an exclusive move, but it's not that useful. Draco Meteor isn't a bad move, but Outrage is better, so it doesn't have that move going for it.
And while it might be fun to put that green guy in gyms (and therefore want it to be atleast a bit strong) I doubt they will be rare since alot of people got a shiny Dratini today/yesterday.

When it comes down to it Dragonite is a good Pokemon and you should probably focus on power up a the best one you have, preferably with Outrage.

But that is just my view. And this is coming from someone who almost never spend any dust and was also fortunate to get a lvl 20 91%IV shiny Dratini.

In the end it all comes down to what you feel is right. After all, you can always get more candies and dust.

I'd pump that candy into your existing level 30 Dragonite and I'm jealous of the moveset.

What was the level of your other two shinys?

Definitely, no.
Atm, shiny pkmn are only for show off so if you must power up a Dragonite I suggest investing in your legacy one (84%). DC is a 3-bar charge move tricky to dodge and really good for gym defending. However, if you're looking for a good sweeper cTM DC for Outrage. In both cases fTM DB for DT to get more DPS.

If this is your only dragonite with draco meteo, it is still worthwhile to power this nice shinny to a certain level which you find it usable.

Shiny draco meteor dragonite is mostly a novelty collector item, which is perfectly usable. But that legacy dragonite has much more value.
For gyms, both defense and offense, legacy one will fare better.
For raids, I only used a dragonite against solar beam ho-oh and nothing else. Lower level specialists usually does the trick.
Anyways, my advice is, don't TM your legacy one, If you feel like you can evolve another dragonite to learn outrage.

I evolved a level 5, 71% dratini all the way, then powered it up to about level 10. It was the best IV shiny I got out of 12. I just wanted to have a shiny dragonite. Don't know what I'm going to do with it. Might give it a bump now and then when I can spare some dust.

I maxed out a 42% shiny Dragonite to level 40 as soon as the event ended. I caught the Dratini at level 29 and had 553 candies when the event ended, so I didn't hesitate. The best thing about always keeping around 1.8 to 2 million stardust is you can do fun, spontaneous stuff like maxing out mediocre shinies. No regrets. It wasn't smart, but I mostly play the game smart so I can do fun stupid stuff like this because, it's just a game and it's pointless if you're not enjoying it.