Excelsior

I'm still relatively new to the Excelsior shard, and I have a question for the mods. I apologize if this has been asked before.

All of the various crafts' runic tools are dropped by elementals of some kind except for carpentry runics. Is there any reason for that? If not, is there any possibility they could be added as a shared drop on wood elementals, in the same way smithy and tinker runics are on ore elementals?

carpentry runics drop from bulk order deeds

I'm sorry, I should've been more clear in what I was asking.

The other runics can be obtained as BOD rewards and also as loot on resource elementals. Carpentry seems to the only one that is only a BOD reward. Why is that?

It makes them more valueable