Siljan I actually prefer it the way it is. I know that amounts can’t be changed now, so when I receive a payment I know that that particular amount is on its way. When the person could change it I’d need to doublecheck what amount was paid and if that were correct. Extra checkboxes I’d avoid whereever possible as they can complicate an interface quickly (maybe not this single checkbox, but if we add one for this feature, then why not for another, and all of a sudden there are plenty checkboxes...)
I’d prefer to keep using my bunq.me link for flexible amounts (people can enter it themselves or have it prefilled by me).
Just my 2 cents. 😁✌️