Hi there, great mod. I like the fact that this mod is even more accurate than the vanilla yellow warning.

Here are some ideas to improve the mod:
1. Throttled warnings - especially for tiles where you can get a large amount of warnings within a short time. Alternatively it can be made into a shortcut key/bar icon for easy switch on/off. Use case - for situation like "I know I don't have this material for construction just let me place ghosts in peace"
2. Filter warnings for composite entities - e.g. LTN input/output of an LTN station should not trigger the warning

Thanks for the suggestions. I've implemented a 30s cooldown to hopefully solve #1. I've not looked at #2 yet but I'm a little confused as to why ghost for those things are created if they aren't expecting to be fulfilled by the placing of an item... maybe some hardcoded exceptions will be required.

Update: Both fixed in 1.2.0.