Tile Palette open causes severe editor lockups, when using a Tilemap prefab instance.

https://issuetracker.unity3d.com/issues/editor-performance-degradation-when-working-with-big-tilemap

This is a bug that was raised back in November 2017. Trying to get more votes on it as I think having tilemaps stored as prefabs is useful for most applications of tilemaps in games, where you might reuse base assets during content creation to save time and get the most out of your assets.

I did not raise the bug initially but it is still here in 2018.2.0b3

If being able to have tilemaps be reusable prefabs seems useful to you, get your votes in on the issue tracker! Only 9 votes to go!