I know this is an old question, but updates for Slickgrid now allow you to disable multiSelect in the grid options:
var options = { editable: false, enableCellNavigation: true, asyncEditorLoading: false, multiSelect: false };
Using this option, clicking while holding ctrl or shift does nothing, and itβs undesirable, you cannot deselect a cell using Ctrl + click or click the selected cell again
pclem12
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