The new column chooser is great, thanks so much! however I would like the option to limit the user's choice of columns they can view or not view. I would like most columns to be 'optional' but, for an example an 'ID' column would remain always hidden (i.e the user cannot choose to view this column), and a 'name' column would be always visible (i.e the user cannot choose this column to be off).

As  I said, I don't know if it is already done or planned, but maybe it could be defined when setting up the column model, to say whether the column is allowed to be switched on or off by the user:

  colModel:[
           {name:'id',index:'id', width:20,hidden:true,columnchooser:false},
           {name:'name',index:'name', width:120,columnchooser:false},
           {name:'location',index:'location', width:80,columnchooser:true},

… and so on. The column chooser script could then read this variable and only make certain columns optional. Perhaps 'true' could be the default setting.