Details panel is very slow when there are many items in an editable array (even if hidden) (was Tile Selection Lag within Tile Set Editor)

Selecting tiles within the Tile Sheet Editor becomes laggy after changing the size and spacing of the tile set.

1. Import Sprite Sheet into Content Browser.
2. Create new Tile Set using the Sprite Sheet.
3. Open Tile Set Editor and set the Tile Size to x = 16, y = 16.
4. Set the grid spacing to x = 2, y = 2.
5. Left-mouse click within Sprite Sheet and begin to select tiles.

Expected: Selection of tiles is quick and responsive.

Outcome: The more you select/de-select the selection times increase and tend to lag.

TileSheet selection time