SpawnUnknown doesn't have much objects

[Shock]

In SpawnUnknown there are not the full list of the objects that designed to be spawned, this is the list of objects that should be included as well:
Crate01, Crate02, WoodBarrel00, WoodBarrel01, XmasPresent00, SwivelChair01, SwivelChair02, Pallet00, MetalBucket00, CardboardBox00.



To avoid some spawn problems, you can set 0 chance of their spawn OnStartup

[Gurt]

The SpawnUnknown is a simple tile to get some random objects spawned in your map and was created before we had the GroupMarkers and RandomTrigger in place allowing for a any randomized combination of spawns you want to do without restricting it to certain objects.
Moving this to the suggestion topic instead as it looks like you want to extend the SpawnUnknown's capabilities.

Meanwhile, use GroupMarkers together with RandomTriggers.