//decorate builds at 256

[dadodasyra]

//decorate takes the "highest block at", but this function wasnt updated to PM5 and an $id !== 0 was hardcoded in it https://github.com/CzechPMDevs/BuilderTools/blob/2.0.0/src/czechpmdevs/buildertools/editors/object/FillSession.php#L136
As air is not 0 anymore it causes the highest block to be the highest one.

By the way there's a 255 hardcoded too, but the world heigth limit is not 256 anymore. (#244)