Yep, these spawners, use regular lootboxes, I don't think RusEdit can handle those spawners well.
And be aware that some trees has no hitbox, just visuals and unharvastable. (2 trees with same name (1 is visual 1 is harvastable), you can check if it's real or not by clicking around the tree and see if it's been selected or not, if not it's not a real tree!)
If you need to populate a big area with trees, bushes, ores then use topology/topologies instead.
Help: https://wiki.rustmapmaking.com/TopoSummary
You have to delete the map in your rust directory or rename your map from neutest to neutest2 (for example), upload it to dropbox, then start the server.