Dynamic Invalidation Box

I’m currently building minesweeper with UMG/Blueprints with plans to make it open source with full tutorial. Each cell is a Widget that is dynamically created, If I create minesweeper map 100x100, It creates 10,000 widgets all running a tick which kills performance. So I need the ability to create a invalidation box as a parent of each widget dynamically, Which I then could toggle on/off mouse over.