Macroscript not jumping to Object's baseobject (modpanel)

Hey guys, after a lot of writing / testing / deleting, I seem to have arrived where I wanted to - a script which toggles a "jump" down to an objects lowest modifier, on a selection change, and when used in a toolbar with visual feedback whether this mode is active. When using my base-jump function on its own, it works fine.. in conjunction with the macro, nothing happens when active (despite my debug messages saying everything works). Does anybody have an idea what might be wrong?

(I'm no scripting wiz as is apparent - I'm rather sure it's to do with the callbacks somehow?)

Thanks in advance for any answers!

macroScript ModifierAutoSelectToggle
	category: "MyTools"
	toolTip: "Visualize AutoModSel Toggle"
	ModAutoSelectActive == true
	on isChecked return (ModAutoSelectActive)
	global ModAutoSelectNoUi
	function ModAutoSelectNoUi = (
		objSel = getCurrentSelection()	
		if objSel.count == 1 do (
			max modify mode
			modPanel.setCurrentObject objSel[1].baseobject
			format "Stack of % jumped to % \n" objSel[1] objSel[1].baseobject
	on execute do (
		if ModAutoSelectActive == true then (
			ModAutoSelectActive = false
			format "ModAutoSelectActive set to: % \n" ModAutoSelectActive
			callBacks.removeScripts id:#ModAutoSelectNoUiCallback
			format "Callback removed \n"
		else (
			ModAutoSelectActive = true
			format "ModAutoSelectActive set to: % \n" ModAutoSelectActive
			callbacks.addScript #selectionSetChanged "ModAutoSelectNoUi()" id:#ModAutoSelectNoUiCallback
			format "Callback added \n"