If it were up to me I would revamp the entire smelting process to include cooking the slag out, bellows, forges, and a whole lot of other factors. Along with adding different metals to increase aspects. But it's not up to me, and I can't code so I can't make a mod for it.
There's a substantial difference between playing tweaked minecraft and TerraFirmaCraft. The LOTRmod is not TerraFirmaCraft for sure, and the realistic mechanics of that reference would definitely not befit the LOTRmod. All three are different games. The adjustments proposed above are fitting for the LOTRmod imo.
While I do think bronze should be collected earlier in the game progression than iron, and this solution would work quite well on most servers, it would make it very difficult (though not impossible) to get to Middle-earth from the Overworld. Since copper and tin do not spawn there, iron ore would be unobtainable and thus it would be very hard to scrounge up enough iron for an iron pickaxe to mine the gold for the ring portal, or collect enough gold from loot chests. It would be possible but a serious pain.
Both scenarios may be regarded on behalf of the entire LOTRmod user community: 1) getting to ME from the Overworld and 2) spawning in ME. However I would find it acceptable if Mevans would only care for the second and optimise for that.