Import/Export Pie with funds as well as %

I was trying to bring existing stock into a pie in equal amounts. This stock is vastly variable in values so I tried to bring it over in the same sum in cash. It didn’t work.
I see that the import and export pie values is set in percentage with a little cash currency value underneath. This makes it just about impossible to use to set an exact amount in cash value. Merely taking your finger off the slider makes it jump.
This can cause a pie to become unbalanced.
Can there please be a selector to switch between cash currency and percentages?