I don't know why this does not work, (or why it is build that way,

in GLMPresentation>>#selection: the transmission for rawSelections is omitted, if #acceptsSelections is false)

But looking at the pragma inspector pane (for compiled methods) for example, it looks like you can add a special inspector
pane that handles selection without opening another (inspector-)pane.

The Pragma inspector shows two lists, a list of pragmas of this method. And a list of methods using this pragma.

If you select an entry in the list of pragmas, there is no new (inspector-)pane, just a new pane in this Pragam-tab.

Here is an example, that I made similiar to the code in the Pragma-Inspect, but
here I use it as another implementation for a collection inspector. add this method at the Collection class.

gtInspectorItemsInX: composite
    <gtInspectorPresentationOrder: 30>
    composite tabulator
        title: 'Collection inspector';
        with: [ :t |
                    t
                        row: [ :r |
                                    r
                                        column: #items;
                                        column: #text ];
                                   
                        row: #object.
                    t transmit
                        to: #items;
                        andShow: [ :a | a list ].
                    t transmit
                        to: #object;
                        andShow: [ :a | a text display:[:x | 'nothing here'] ].
                    t transmit
                        to: #text;
                        andShow: [ :a | a text display:[:x | 'nothing here'] ].
                    t transmit
                        from: #items;
                        to: #text;
                        andShow: [ :a | a text display: [ :x | (GTObjectPrinter new asTruncatedTextFrom: x) asString ] ].
                    t transmit
                        from: #items;
                        to: #object;
                        andShow: [ :a |
                                    a
                                        custom:
                                            (GTObjectVariablesBrowser new) ] ]