How should I set up a loot filter to sort gear faster?

Give potential upgrades a distinct name color, then use rules for each gear slot. You can combine item type, power range, rarity, and affixes you want. Keep must-have affixes separate from less important ones, so an item can still stand out if it has a useful mix from the optional group. When sorting, check the colored items and mark the rest as junk.

Separate rules for different item categories can make the filter easier to read. For example, unique items and different kinds of charms may need their own conditions. If you also want to mark items with Codex upgrades, give those a different color and put that rule after the potential-upgrade rules so an upgrade still stands out.

The initial setup takes some work, but you can adjust it as you learn which affixes matter to you. An affix that starts as optional can become required later.