It is now possible to change allocated scientists and engineers on a project without opening extra GUIs, directly in base GUI using mouse scrollwheel.
Normal scroll +/- 10 scientists or engineers
CTRL + wheel +/- 1 scientist or engineer
The step is configurable via options.cfg, if you don't like the defaults.
oxceManufactureScrollSpeed: 10
oxceManufactureScrollSpeedWithCtrl: 1
oxceResearchScrollSpeed: 10
oxceResearchScrollSpeedWithCtrl: 1