Right now auto exchange can’t really be used for exchanges where the target worth is many hundred times more than the source, since there is not enough numerical digits to input.
Say, for example, the exchange rate EUR→HUF is between 313 and 327, where the reverse rates would result 0.003105 and 0.003067.
First, it is almost impossible to get that info from app since it shows “exchange rate between 0.0031 and 0.0031”, which is not really informative.
Second, the input field can’t accept more than 4 fractional digits, so… obviosuly not pretty useful.
As UI wise I would say the easiest and natural would be for me to input HUF and input EUR and the app could calculate the exchange rate, it may offer a verification step (button) but otherwise it’s not really needed, and it could internally calculate it to precise digits.
The most extreme example (not supported by but for the sake of possibilities and UI planning) and thus the required precision in our current world) would be to exchange from Iranian Rial (IRR) to Kuwaiti Dinar (KWD) which has 138575:1 exchange rate so 0.00000721627 is the current rate. (Visibly entering rates in so small fractions is not easy for humans, but that’s nother philosophical question: whether xchange rate input shall be enabled in reverse notation or not.)
(A more realistic example is HUF→GBP where the rate is between 0.00268096 and 0.00279329 for the last month, which is 1/358 to 1/373.)
Would be nice if the app UI would help a bit more regarding such exchanges. Thanks!