Many dungeon crawlers have switch/door or plate/door mechanics. Link lines would be one way to annotate these. Like many things, this is just "nice to have", not a requirement.
Another style I've seen would be to simply color the related squares, which is already possible in Gridmonger.
My technique is just to use text labels like "S3" for a switch and "D3" for a door, but it's a bit messy. Link lines offer the possibility of hiding them until needed.
Many dungeon crawlers have switch/door or plate/door mechanics. Link lines would be one way to annotate these. Like many things, this is just "nice to have", not a requirement.
Another style I've seen would be to simply color the related squares, which is already possible in Gridmonger.
My technique is just to use text labels like "S3" for a switch and "D3" for a door, but it's a bit messy. Link lines offer the possibility of hiding them until needed.