Thema: Great River tokens: silver for gold = gold for silver!

I know gold tokens are hard to get, while silver are kinda easy, but wouldn't be better to have the same exchange ratio for silver vs gold as well for gold vs silver tokens? I get 5 silver tokens from one gold token and one gold token from 25 silver tokens... what if I make a mistake and want back the tokens I just exchanged? I mean, what if I could trade 1 gold token for 15 silver and 15 silver for one gold? Just as it happens in Enedwaith, Evendim, Angmar and so on...

The token exchange rate in Enedwaith is the same as the rate in Great River.

The token exchange rate in Evendim is equal both ways

I guess they dont want you saving inventory space by converting all your Silver to Gold, and then just converting Gold back to Silver at the same rate?

Or, to put it another way, there's meant to be some "cost" associated with converting; the two currencies arent supposed to be completely fungible, or else you could just express everything in purely silver- or gold-token prices, basically removing any distinction between the two.

Evendim's are nicer, I can exchange either one as I need to save a bit of space. Then again, those are Bronze and Silver, not Gold and Silver.