I've got a working version of this for EW patch 1, using basic pawn-cycling as the unit list boxes are scrolled left and right. The pawns instantaneously swap which is a bit jarring, but they at least line up with the unit list boxes.
I've also updated the upk-side so that it all works properly with keyboard/gamepad controls (I've only tested keyboard, but they use the same OnUnrealCommand callback as gamepad) as well as with the mouse. Honestly, XMTS did the heavy lifting with all of the required Flash changes -- the upk side stuff was pretty simple.
The full mod has 14 distinct changes, which since I'm working within the Long War EW development, are in 14 distinct upk_mod files for UPKmodder. 6 of the files are for Flash changes, and 8 are for Unrealscript changes. Currently I'm awaiting either XMTS or JL to verify my changes before posting up the complete mod.
It will likely need to be translated into wghost's format for easier installation. To fit the functionality to handle the Mouse Event callback I had to resize one of the functions, which will prevent translation into a ToolBoks-compatible mod.