Demo attached.
I emulate here problem with CudaText: run the demo, try to move 1st vert splitter to the right-- it moves a little and stops! it's blocked by MinSize of 2nd splitter. Changing that MinSize don't help- it's already mininal value =1.
Users want this behaviour: when I move 1st splitter to right, it must move, reducing width of Panel2 (it cannot reduce Panel3, it's minimal).
Linux gtk2 x64, Lazarus trunk