Methods of getting obsidian early in the pack are either (1) mining or (2) extremely slow. Void upgrades require eight obsidian. It may be worth either drastically reducing the amount of obsidian for a void upgrade or adding a void crystal recipe.

(I understand, however, that there is an incentive, if void upgrades are expensive, to store more items. Is this the idea? After all, many items are needed long into the pack.)

Voiding things is mostly discouraged, but I don't think that really factors into it. We're using the vanilla recipe for the item from StorageDrawers.

Early game automation is expected to be fairly slow, with alternatives requiring manual effort. By HV the time per obsidian block from solidifying lava is not so bad, but you also get access to the Igneous Extruder around then. Void crystals as an alternative for Dark Steel are an incentive to get an Atomic Reconstructor made after setting up DML.

We don't really expect players need all that much obsidian. It's not too onerous to mine the obsidian you need for bootstrapping dark steel, and after that most of the obsidian you end up needing is dusts for petrotheum (which you can just get from DML).