prestigation or control flame?

[Camman1984]

as a sneaky rogue about to take mage initiate (am taking find owl as my level 1), the idea of being able to snuff out flames, or even make little images in the flames appeals to me, i know its not a great spell but i have some ideas.

my question is, can all the stuff in control flames be done with simple prestigation, or does it have enough niche to bother taking?

I also have this fluff based idea that she is going to become a dragon warrior so may use control flame to have little braziers with firey dragons on her dress armour, but thay s another story ;)

also,

I have 1 more cantrip to pick, leaning toward either message (for scouting purposes) of green flame blade for a dash of AoE. I already have booming blade as my attack cantrip from being an elf. only problem is my intelligence gives me 1d8-1 as splash damage which sucks

[Joe the Rat]

If it's just for snuffing torches and making dragon images, prestidigitation will cover you (snuff or light flame, simple images/illusions which could be illusory dragon-shaped flames), and provide a lot of other utility (incredibly minor creation/moving objects, reflavoring poisons to match what you're putting them in, recoloring your hair, etc).

If you want to do more with fire, control flames has more uses. You can snuff a 5' cube (for example, an entire bonfire), your shapes (which can persist for an hour) are actual flames, you can change flame color, change intensity (dimming to create more dim light to exploit, doubling the intensity as a surprise), or expand/ move it around (as a distraction - the fire jumps onto the firewood, and then onto the tent).

Presto for more effects, Control flames if you want to keep it fiery.

On your last: greenflame also adds fire to your initial attack (+1d8 at 5, etc.) so it has utility in spite of the low carryover. B ut with booming, you have plus-damage covered. You could instead grab Create bonfire: with the low Int, it's an easy save, but it presents an obstacle, and a source to use control flames, and you're not exactly using concentration for anything else. It'll also give you a big fire faster than creating flames with presto.

Message is a good choice, for exactly the reasons you note. That's probably most useful (although you could have your familiar deliver a note).

[JumboWheat01]

I can't help but always have the "I'm a <insert class here>!" cantrips. They may not be the most useful, but they're just so flavorful.

[Camman1984]

I have also decides that to go along with my fiery theme, I am going to attach a couple of torches the the front of our ship and have an animated fiery dragon as our figurehead instead of some boring mermaid bust, I may regret it when it sets fire to the rest of the ship but the image in my head is fairly cool and I would just have to refresh the control flame each hour