Potential solutions may include:

Faster traversal mechanics
New waypoints
Dynamic map compression based on Path of Exile 2 Currency objectives

New Act Incoming?

Jonathan Rogers teased that a new Act might be included in 0.3.0-or at least soon after.

The campaign currently features three Acts in Early Beta.
Act 4 gameplay was shown at ExileCon 2023, fueling speculation.

If Act 4 drops, it may also bring:

New environments and bosses
Lore progression
Class-specific story missions

A fourth Act could also reduce the need for Cruel Difficulty repeats, possibly shifting the leveling curve and improving pacing.

What Else Could Be Coming?

GGG is famously secretive about their league mechanics, but based on previous updates, 0.3.0 may also bring:

A new challenge league mechanic with temporary crafting systems or combat modifiers.
More Unique items, especially class-specific ones.
Potential endgame adjustments as cheap Path of Exile 2 Currency the base content grows.
Additional minion archetype balancing, following community feedback.