How about we could use 0* to 2* Fire Crystals (at a >1 rate per needed Token) to replace needed Forge/Grim/Primal Spark Tokens to get stuffs from Brinks?

The desperation among players for something to do with 0* to 2* Fire Crystals seems to range from "{shrug} Doesn't take up space." to "Please, if I can't at least chuck them out the window, I'll go that way myself Real Soon Now!1!!"

I'm somewhere in the middle, I'd like to be able to use them for something that is somewhat useful.

For some reason, Brinks' Forge/Grim/Primal Spark Tokens came to mind today. How about we could use 0* to 2* Fire Crystals to replace needed ...Spark Tokens to get stuffs from Brinks?

The rate would have to be at a return rate for Crown value that's less than buying them, naturally.
It's sorta common knowledge that a ...Spark Token equals 100cr (if you buy the most expensive Trinket for 100 and dump that in a Vendor you get 10kCr).

Price of Fire Crystals
0*, Cracked, 50Cr for 5 from Vatel: 10Cr per Crystal
1*, Dim, 125Cr for 5 from Vatel: 25Cr per Crystal
2*, Warm, 85E (~6500Cr) for 50 from Supply Depot: ~130Cr per Crystal

For Completeness sake. (Some rounding there to get even numbers...)

3*, Glowing, 175E (~13kCr) for 50 from Supply Depot: ~250Cr per Crystal
4*, Shining, 350E (~26kCr) for 50 from Supply Depot: ~500Cr per Crystal
5*, Radiant, 700E (~52kCr) for 50 from Supply Depot: ~1000Cr per Crystal

So, with that in mind, my suggestion is to make Fire Crystals be usable as 'jokers' for Forge/Grim/Primal Spark Tokens at the following rate:
20 0*, Cracked may replace 1 Token
8 1*, Dim may replace 1 Token
2 2*, Warm may replace 1 Token

And for completeness sake

1 3*, Glowing may replace 1 Token
1 4*, Shining may replace 2 Tokens
1 5*, Radiant may replace 3 Tokens

There could be an additional requirement to have at least 1 (or at least 50%) of the needed Tokens be actual Forge/Grim/Primal Spark Tokens.

It would give players the option to get Trinkets or Materials they need or even to sell, with stuff they don't otherwise need.
I think the profit gain even with re-selling would be minimal. People need Materials for their Sprites, and some like to dump them into Treasury for Trophies (which would speed up the need to sink Crowns in as well to craft the Trophies).
Someone like me likes to get Trinkets to make loadouts underneath costumes stick with a colour theme even.

(Plus, a lazy player could buy the Crystals from Vatel to turn them into Materials to feed his Sprite; crown sink!)

The only possible side-effect I see is that it could raise the perceived Material worth of the rarer ones from Token-equivalent price to Crystal-equivalent price. But most materials already sell for considerably less than that, and the rarer ones are already there.
An additional source would most likely lower overall reselling worth, no?

Anyway, thanks for reading. If my math went sideways somewhere, please tell me!