Keyman not Recognized by "Set Keyboard Layout To"

Found a more reliable solution with AppleScript:

-- it looks like it needs to execute twice to work reliably.
changeKeyboardLayout("Squirrel")
changeKeyboardLayout("Squirrel")

on changeKeyboardLayout(layoutName)
	tell application "System Events" to ¬
		tell application process "TextInputMenuAgent" to ¬
			tell menu bar item 1 of menu bar 2
				click
				delay 0.1
				click menu item layoutName of menu 1
			end tell
end changeKeyboardLayout