The "make rock short sword" job allows materials to be selected, and native metals have the line in their raws "no swords until you can pick mats" (though per
Bug 3098, the actual picking is a bit bugged)
Native metal properties should thus be upgraded to have their proper [MAX_EDGE:10000], giving them the "Sharp blades" usage. I'm not sure how sharp raw adamantine would be, as it does have that same no-swords comment but does bypass the entire endgame strand extraction chain.
Since items made of native metals are essentially just metals, but cold-worked with masonry, they should behave more like their smithed counterparts.
Native metal furniture should use metallic sprites rather than stone ones. This could be a new token, [GRAPHICS_CATEGORY:FURNITURE], with arguments for WOOD, STONE, METAL, GLASS, and whatever else gets supported or initially wrapped up in hard code by the tileset.
Native metal weapons (and miscellaneous goods) should also be meltable to produce bars of standard metal. Since they are already [ITEMS_HARD], they can't just have [IS_METAL] added to them without producing bloat entries in the forge.
[METAL_ORE] could be turned into a proportional quantity and queried for meltability, but if melt returns can be customized, better to go the whole way and decouple it from the ore token.
These are some proposed tokens to control melting behavior.
[MELT_SPECIAL:BAR:NONE:INORGANIC:GOLD] is essentially two tokens in one. If the material has [IS_METAL], it should essentially default to BAR:NONE:NONE:NONE creating bars of the input material. This syntax allows material templates to use this tag without manual input. Setting all arguments to NONE (or just supplying it as the 1st, if it can be cleanly reduced) disables all melting, even if the item is metal.
[MELT_AMOUNT:MATERIAL_SIZE] produces melt yield dependent on the input's material size and the [WAFERS] token. This can be set to a specific value, overriding the default calculation and producing that quantity like in a reaction. This is primarily for fine-tuning things, so that melting modded weapons that normally cost 5+ bars doesn't make more than the ore produces. I'm not sure how the logic for producing non-dimension-150 melt items works.
It could alternatively set a maximum amount, so that melting native metal items could produce 0-4 bars based on the material size but nothing more.