Wire Parameters on Scripted Texturemaps

Hello, I am fairly new to max script, so I apologize if this is a redundant question. Anyways, I am trying to find out why I cant wire any parameters in maps that are placed in map buttons in texture-map scripts. Heres an example of a pass-through texture script that extends output-

plugin textureMap test_map
name:"Test_Map"
classID:#(0x7f14579d, 0x5caf6ea9)
extends:output
replaceUI:true
version:.1

(
parameters main rollout:tmroll
(
passthrough_map type:#texturemap ui:testmap on passthrough_map set val do (delegate.map1 = val)
)--end params
rollout tmroll "Test_Map_01" width:#mtlEditor
(
mapbutton testmap "Passthrough Map" width: 160
)--end rollout
)--end plugin

The map works fine as a pass-through texture, but say if I put a checker map in the slot, none of the checker parameters show up in the Parameter Wire dialog or the Track View. I am not sure if I am missing anything or if texture maps inside scripted texture-maps aren't wire able. Any help would be greatly appreciated.