inset code is not working

(
	selObjsArr = selection as array
	for i in selObjsArr do
	(
		select i
		if classOf i != editable_poly do convertToPoly i
		subobjectLevel = 4
		topFaces = #{}
		gfc = polyop.getFaceCenter

		for f = 1 to i.numfaces do
		(
			if (gfc i f).z == i.max.z do append topFaces f
		)
		
		polyop.setFaceSelection i topFaces

		i.insetType = 1
		i.insetAmount = 200
		i.EditablePoly.buttonOp #Inset
		
		i.extrusionType = 0
		i.faceExtrudeHeight = -600
		i.EditablePoly.buttonOp #Extrude

		clearSelection()
	)
)

thank you miauu
i tested this code~
but that is not work still ~

but
max modify mode is work
but in many object , that is very slow

is there good idea ?

Check this example. It doesn't require modify mode to be active

selectedFaces = polyop.getFaceSelection $

-- Inset
$.EditablePoly.SetSelection #Face selectedFaces
$.extrusionType = 2 --by polygon
polyop.extrudeFaces $ selectedFaces 0.0
$.outlineAmount = -10
$.EditablePoly.Outline()

-- Extrude
polyop.extrudeFaces $ selectedFaces -5.0

redrawViews()

thank you for good code~~
really really fast~