Feature Request: MultiSpool Set Amount for "Start Without Printer"

[vsnapp]

Is your feature request related to a problem? Please describe.
I would like to make exactly 1kg of filament from multispool using "Start Without Printer" on the palette 3 pro multispool option.

Describe the solution you'd like
A menu to set a specified amount of filament (in meters or grams) to extrude when using multispool without printer.

Describe alternatives you've considered
Weighing spools to make them close to 1kg but it is hard to get exactly 1kg of filament on a roll.

Additional context
n/a