I concur that phirius tokens would be ideally put in the currency window.
The current max tokens per a day from daily quest is 125 tokens. 4 minis costing 30 each leaves 5 tokens per a day. This also doesnt account the random token rewards from the minis. There is a surplus.
And since most characters do not do minis, there is even more surplus.
I always wondered why the siege badges and pioneer sigils made the cut for the currency window, but not the phirius tokens.