Nice one. I think the fiat amounts could use a hover state, hand cursor and click event. Took me a bit to realize I could select those amounts and edit them as well. Also, deep-linking to an amount could be helpful if you want to send it to someone so they can see how much it is in their currency.
More currencies and a revised layout.
https://satsconverter.io is here to help you transition to a sats standard.

Discussion
👍🏼 for sure! Will have to add these.
Another aspect I think could be useful would be to add a date picker so it could get you the conversion at any given date in the past. Also with deep linking.
Do you know anyone interested in implementing this?