Time consuming callbacks in customizer

Building upon How to hook on customizer section expanded/active/opened event? question, perhaps you could listen for the section (or panel) expanding like this to unbind functions from the previuos section and bind them to the current section.

(function ( api ) {

    // Wait for Customizer to be ready
    api.bind( 'ready', function() {

        // "cache"
        var currentPanel,
            currentSection;

        // Listen for panel expands
        api.panel.each( function ( thisPanel ) {
            thisPanel.expanded.bind( function( isExpanding ) {
                if (isExpanding) {
                    unbindCustomFunctions( currentPanel )
                    bindCustomFunctions( thisPanel );
                    currentPanel = thisPanel;
                }
            });
        });

        // Listen for section expands
        api.section.each( function ( thisSection ) {
            thisSection.expanded.bind( function( isExpanding ) {
                if (isExpanding) {
                    unbindCustomFunctions( currentSection )
                    bindCustomFunctions( thisSection );
                    currentSection = thisSection;
                }
            });
        });
    });

    function bindCustomFunctions( sectionOrPanel ) {
        // Code
    }

    function unbindCustomFunctions( sectionOrPanel ) {
        // Code
    }

} ( wp.customize ) );