In current game, my faithful survivor never fails to prioritize fueling the fire with Gilded Lumber before falling back to more mundane Wood Bundles he also happens to have in his pockets, no matter how many times I yell at him about not burning gold/copper-plated items for warmth.
Better way of working would be to have survivors prioritize lowest tier items from inventory for both fueling and building (since building with higher tiers also seems to have no benefit).
Bonus if max tier survivor is allowed to use is configurable.
This is why we're able top set their behaviours now.
Simply disallow them from fueling or building to prevent the undesirable use of materials.