Subgrid button enable rule

I have 2 issues.

First issue: Trying to hide OOB button in subgrid(Ribbon), based on user role(by calling javascript). Is it possible?

Second issue: Hiding OOB button is not possible through "enablerule"javascript, so alternative I tried to disable button by using "enablerule"/javascript. Here is following code which reflects above. Still is NOT working, but for main form Ribbon button, the below code is working.

Can anyone please help me?

<Groups Id="Mscrm.SubGrid.quote.MainTab.Groups"><Group Id="Mscrm.SubGrid.quote.MainTab.Management" Command="Mscrm.Enabled" Sequence="10" Title="$Resources:Ribbon.HomepageGrid.MainTab.Management" Description="$Resources:Ribbon.HomepageGrid.MainTab.Management" Image32by32Popup="/_imgs/ribbon/newrecord32.png" Template="Mscrm.Templates.Flexible2"><Controls Id="Mscrm.SubGrid.quote.MainTab.Management.Controls"><Button Id="Mscrm.SubGrid.quote.NewRecord" ToolTipTitle="$Resources(EntityDisplayName):Ribbon.SubGrid.MainTab.New" ToolTipDescription="$Resources(EntityDisplayName):Ribbon.Tooltip.New" Command="Mscrm.NewRecordFromGrid" Sequence="10" LabelText="$Resources(EntityDisplayName):Ribbon.SubGrid.MainTab.New" Image16by16="/_imgs/ribbon/NewRecord_16.png" Image32by32="/_imgs/ribbon/newrecord32.png" TemplateAlias="o1" /><Button Id="Mscrm.SubGrid.quote.AddNewStandard" Command="Mscrm.AddNewRecordFromSubGridStandard" Sequence="20" LabelText="$Resources(EntityDisplayName):Ribbon.SubGrid.AddNew" Alt="$Resources(EntityDisplayName):Ribbon.SubGrid.AddNew" Image16by16="/_imgs/ribbon/NewRecord_16.png" Image32by32="/_imgs/ribbon/newrecord32.png" TemplateAlias="o1" ToolTipTitle="$Resources(EntityDisplayName):Mscrm_SubGrid_EntityLogicalName_MainTab_Management_AddNewStandard_ToolTipTitle" ToolTipDescription="$Resources(EntityDisplayName):Mscrm_SubGrid_EntityLogicalName_MainTab_Management_AddNewStandard_ToolTipDescription" /></Controls></Group><CommandDefinitions><CommandDefinition Id="Mscrm.AddNewRecordFromSubGridStandard"><EnableRules><EnableRule Id="new.quote.EnableRule2.EnableRule" /></EnableRules><DisplayRules><DisplayRule Id="Mscrm.ShowForOneToManyGrids" /><DisplayRule Id="Mscrm.AppendToPrimary" /><DisplayRule Id="Mscrm.CreateSelectedEntityPermission" /><DisplayRule Id="Mscrm.AppendSelected" /><DisplayRule Id="Mscrm.HideAddNewForChildEntities" /></DisplayRules><Actions><JavaScriptFunction FunctionName="Mscrm.GridRibbonActions.addNewFromSubGridStandard" Library="/_static/_common/scripts/RibbonActions.js"><CrmParameter Value="SelectedEntityTypeCode" /><CrmParameter Value="PrimaryEntityTypeCode" /><CrmParameter Value="FirstPrimaryItemId" /><CrmParameter Value="PrimaryControl" /></JavaScriptFunction></Actions></CommandDefinition><EnableRule Id="new.quote.EnableRule2.EnableRule"><CustomRule FunctionName="IsUserRoleAdmin" Library="$webresource:Quote_main_library.js" Default="false" InvertResult="true" /></EnableRule>

function IsUserRoleAdmin()
{
         var currentUserRoles = Xrm.Page.context.getUserRoles();

         var isAdmin = false;
          for (var i = 0; i < currentUserRoles.length; i++)
          {
             var userRole = currentUserRoles[i];
            //check admin role 
            // For testing, assume it returns false  
                    //  if(userRole == "admin guid")
            // {
            //  isAdmin = true;
            // }
           }

 return isAdmin;
}