Tastes good even without steeping which is a surprise considering all the cream and Custard concentrates!
If you want a more pronounced mint flavour, increase the Peppermint by about 1-2% and for a cooler throat hit the Koolada could also be increased by 1-2% as well.
I might omit the Dulce De Leche on future mixes as I don't think it's entirely needed and the current version contains Diketones, so if this is an issue, it should be possible to omit it from the mix. Perhaps push the percentage of the other cream/Custard concentrates by 1-2% to compensate.