Opening many cells at the same time repaints them individually

[Namdrib]

At the moment, opening many cells at the same time repaints them individually, which gives a
bit of a "cascade" effect, as seen in the following .gif

See if there is something that can be done to remedy this
Perhaps using bfs instead of dfs
Or using a flag to only visually open them once they are all opened
Or maybe not repainting till they're all done

[Namdrib]

This also occurs when mines are triggered