The view of hundreds of lines of TK widget definitions may seem messy and daunting, but that is probably just bad organization. I find that having all the graphic layout in 1 location(file); well commented and visually organized; shows the whole picture in one place. PerlTK is relatively clean, compared to X11R3 with Sony widgets, where I started doing GUIs.

Draw your layout; and have a naming convention for widgets and variables that supports your nesting or management scheme. Then segment the callbacks (action code) into separate modules that are related... all input in one, all validations in another; or 1 module per GUI manipulation object/widget.

Trying to do incremental widget instantiation in a 'workproc' is probably beyond PerlTK.

Comment...Describe why...think maintainability.