How to forbid resource exchange partly?

Does someone has idea how to disable player share lumber while they can still give/receive gold? seems WE does not provide this function.
THX

tried setting both small step and big step for the wood to 0?

There is just a setting for both, not for wood only.

oh.. right

well then just make a trigger that gives wood back if its shared. Or disable both sharing and make a -give for gold.

Is there any other solution?
I didn't want to use trigger to emun for it does not look nice.

Seems that trigger is the only solution