hiddenSelectionTextures not showing

[Mr H. 402]

I want my object to have a zone where textures can be changed so I used a selection as hiddenSelectionTexture
here is my model.cfg

class CfgSkeletons
{
    class Skeleton
    {
        isDiscrete=0;
        skeletonInherit="";
        skeletonBones[]={};
    };
};
class CfgModels
{
   class Default
   {
       sectionsInherit="";
       sections[] = {};
       skeletonName = "";
   };
   class MRHObject : Default
   {
       htMin = 60;          // Minimum half-cooling time (in seconds)
       htMax = 1800;        // Maximum half-cooling time (in seconds)
       afMax = 30;          // Maximum temperature in case the model is alive (in celsius)
       mfMax = 0;           // Maximum temperature when the model is moving (in celsius)
       mFact = 1;           // Metabolism factor - number from interval <0, 1> (0 - metabolism has no influence, 1 - metabolism has full influence (no other temperature source will be considered)).
       tBody = 37;  // Metabolism temperature of the model (in celsius)

       sections[] =
       {
           "camo","core"
       };
       skeletonName = "Skeleton";//"OFP2_ManSkeleton";
   };
   class MRH_EL_Button : MRHObject {};
   
};  

here is my config

class MRH_ElevatorButton_Base: Items_base_F 
{
	author = "Mr H";
	mapSize = 0.07;
	class SimpleObject 
    {
		eden = 1;
		animate[] = {};
		hide[] = {};
		verticalOffset = 0.131;
		verticalOffsetWorld = 0;
		init = "''";
	};
	editorPreview = "";
	//_generalMacro = "Land_BottlePlastic_V2_F";
	scope = 2;
	scopeCurator = 2;
	displayName = "ElevatorButton";
	model = "\MRHMiscItems\Models\ElevatorButton\MRH_EL_Button.p3d";
	
	icon = "iconObject_circle";
	editorCategory = "EdCat_MRH_Misc";
	editorSubcategory = "EdSubcat_MRH_Props";
	vehicleClass = "Small_items";
	destrType = "DestructNo";
	cost = 100;
	hiddenSelections[] = {};
	hiddenSelectionTextures[] = {
    "\MRHMiscItems\Models\ElevatorButton\Data\button.paa"
    };
	// ThingX
	simulation = "thingX";	
	
	
};
class MRH_ElevatorButton : MRH_ElevatorButton_Base
{
	hiddenSelections[] = {"camo"};
	hiddenSelectionTextures[] = {
    "\MRHMiscItems\Models\ElevatorButton\Data\button.paa"
    };
};

here is my issue: if I don't add "camo" to hiddenSelections (see the _base model) both selection will show when the object is placed in eden but setObjectTextureGlobal command doesn't work (obviously).
However if I  add the camo selection the "camo" zone texture (2nd cfg entry) the camo selection won't show when the object is placed but setObjectTextureGlobal works and the texture can be set afterwards.
This (probably old) guide http://fab.ofp.free.fr/Tutorials/Hidden_Selections.htm seems to indicate that this is normal behavior. However I've seen plenty of objects where the default texture will show when placed and can be changed. I must be missing something but what?

Here's a pic of both objects in game for clarity

[Mr H. 402]

Edit for future reference : I'm just a freaking idiot. hiddenSelectionTextures should be hiddenSelectionsTextures