PlatinumAltaria

In Minecraft they recently added the offhand slot, which allows you to carry an item in your other hand. I'm suggesting a tool-belt; an item worn in the leggings slot that adds another slot to the opposite side of the hotbar. The tool-belt itself would work like the old quiver; it would have 4 slots into which only tools could be put (saws, chisels etc), and when worn would allow the player to quickly switch from their main hand to the tool-belt, perhaps with the caps lock key (being on the opposite side to the f-key). This would free up some space in the hotbar, potentially removing 4 necessary tools you feel are too important to leave at home. The belt would be crafted with leather and iron so as to keep it later in the gameplay, and would take up a valuable armour slot to further balance the freed space.

Ok fair enough. To be honest the best solution would be to make the weight limit configurable.

And how would one be incentivised to advance if the limit isn't swaddling? If I can get by lugging rocks around on my own there's no reason to go any further.

The whole point of a weight limit is realism...

A cart isn't exactly advanced technology, you can make a sled with just sticks and logs. And it makes absolutely no sense to be able to lug a metric tonne of stone around on your back with no ill effects. For the sake of realistic gameplay there needs to be a burdensome limit on carry weight, because if there isn't there will be no reason to advance; the exact reason people tamed horses in real life was to drag stuff around. Also, not to be rude but people in the stone age were not known for their fancy building.

Not gonna lie, those women seem prettyoverburdened.

You can't have weightless items, lugging around 300 sticks is just as ridiculous as several metres cubed of stone. And since they're adding carts and such you probably won't be carrying much on your person anyhow.

I just took the name of the real-world weights, the main point was the ratio. Though if you only use one unit you're going to run into "10000 wt." at some point, for super-heavy materials like gold a stack of ingots would be unbearable.

Given the game begins in the stone age it hardly seems logical to have "historical context". Though the idea of an army of slaves pleases me.

Why have molds that can cast multiple ingots, why not just add metal casts that can be reused. Pouring the metal from the crucible would save a lot of hassle.

Rather than procedurally generating new ores, you could use the dozens of metals we use to create different alloys in the real world; Manganese, Chrome, Nickel, Molybdenum and Boron, to name a few. These elements might spawn in extremely low quantities, and have very specific purposes, such as increasing the durability or changing the colour (because who doesn't love custom colours). If you give each metal a predictable but different quality you make sure there is no "best alloy", rather each one has a specific function; I for one would spend hours trying to find that perfect blue coloured alloy.

On the subject of units and the weight limit, there's a handy ratio: 16 Ounces to a Pound, 16 Pounds to a Stone. (Since 16 is a Minecraft-y number it rather justifies changing the ratio between the units.) The average man can lift around 8 stone (another Minecraft-y number), or in this case 128 pounds, or 2048 Ounces. By capping the carry limit at this top point, it incentivises players to progress technologically, but doesn't force them to drag a cart around their base with them; you can easily transfer a sack of flour between chests, or carry a few rocks over to the build site from a cart. However, it's small enough that the player can't just lug 400+ logs around in their inventory. Suddenly the stone age feels harsher.