Feature Proposal: custom distribution of bill over the selected members

short:
When adding a new bill, the distribution of the amount over the selected members should be modifyable and not evenly.

usecase:
our main use case is when someone orders meals for the coworkers. As every menu could cost a different amount, an even splitting and distribution of the amount is not what we want.
With the current implementation a workaround would be that every single item on the bill (from the restaurant) would lead to a separate bill between the buyer and the member.

proposal:
"For whom" should have a checkbox "custom" which switches from checkboxes to textboxes (alternatively: when checked, a member entry gets a textbox). Also in this state the "How much" textbox gets readonly.
Now you can insert custom amounts next to each member which updates the now readonly "How much" box. Also this of course has an corresponding effect on the data behind.