Modifier Plugin | ScriptSpot

So I'm probably just missing something really stupid, but I'm trying to extend the Unwrap UVW modifier. When I do so, however, my modifier looses all of the original functionality; aka I can't select anything. My code doesn't even have functionality yet, but here it is.

plugin modifier uvwSmoothGroups
	name:"Unwrap UVW - SmGr"
	extends:uvwunwrap
	classid:#(0x3b0ed8b6, 0x6f749efc)(
	
	parameters main rollout:SmoothingGroups(
		smGr type:#indexTab
	)
	
	rollout SmoothingGroups "Smoothing Groups" width:160 height:96
	(
		checkbutton ckb1 "1" pos:[15,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb2 "2" pos:[31,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb3 "3" pos:[46,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb4 "4" pos:[63,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb5 "5" pos:[79,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb6 "6" pos:[95,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb7 "7" pos:[111,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb8 "8" pos:[127,4] width:18 height:18 enabled:true checked:false
		checkbutton ckb9 "9" pos:[15,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb10 "10" pos:[31,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb11 "11" pos:[47,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb12 "12" pos:[63,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb13 "13" pos:[79,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb14 "14" pos:[95,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb15 "15" pos:[111,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb16 "16" pos:[127,20] width:18 height:18 enabled:true checked:false
		checkbutton ckb17 "17" pos:[15,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb18 "18" pos:[31,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb19 "19" pos:[47,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb20 "20" pos:[63,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb21 "21" pos:[79,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb22 "22" pos:[95,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb23 "23" pos:[111,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb24 "24" pos:[127,36] width:18 height:18 enabled:true checked:false
		checkbutton ckb25 "25" pos:[15,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb26 "26" pos:[31,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb27 "27" pos:[47,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb28 "28" pos:[63,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb29 "29" pos:[79,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb30 "30" pos:[95,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb31 "31" pos:[111,52] width:18 height:18 enabled:true checked:false
		checkbutton ckb32 "32" pos:[127,52] width:18 height:18 enabled:true checked:false
		button btnClr "Clear" pos:[16,77] width:55 height:16
		button btnClrAll "Clear All" pos:[88,77] width:55 height:16
	)
)

[EDIT] Just to clarify:
1) I do get a modifier

2) It does carry over the Unwrap UVW modifier's rollouts

3) My rollout does appear

4) The Unwrap UVW ui and rollouts can interact with the mouse but not shortcuts, and most appear to have no function.

4a) Exception: the Open UV Editor button does open a UV Editor window, which is empty as if there are no faces in the object.

4b) Enabling FaceSelectionMode via mouse is the only button resulting in visual difference in the scene. It creates the yellow "projection" icon at the home grid's origin, no matter what the objects coordinates.

5) My modifier shows seams in the viewport.

I have been referencing the help extensively. I even copied this code from the Scripted Modifier Plugins help, changed replaceUI: to false and it all works.

plugin modifier myMod
name:"Supa Mod"
classID:#(685325,452281)
extends:Bend replaceUI:true version:1
(
  parameters main rollout:params
  (
    bendamt type:#float animatable:true ui:bendamt default:0.0
    on bendamt set val do delegate.angle = val
  )
  rollout params "SupaMod Parameters"
  (
    spinner bendamt "Bendiness: "
  )
)

I also deleted everything but the plugin declaration in mine, and still nothing. I had originally thought that maybe the Unwrap UVW modifier wasn't extendable, but my rollout shows up, so according to documentation, it is extendable. Also I tried using the UVW Mapping, modifier as an extend and got an error saying it couldn't be extended, which the Unwrap UVW modifier does not give.