When speedups of different types are limited and you have to choose where to apply them first, the right answer depends on which of your two main queues currently has the longer remaining timer and the higher-impact item queued.
Compare remaining time, not queue type
Rather than defaulting to always prioritizing one queue type over the other, check which specific queue — building or research — currently has more time remaining, and apply available speedups there first, regardless of category.
Weigh impact, not just time saved
A shorter queue with a high-impact unlock (a key research breakthrough, a critical building tier) can be worth prioritizing over a longer queue with a more routine item, even if it means less total time saved in the abstract.
Research generally compounds more than a single building
As a general tendency, research unlocks tend to apply account-wide and permanently, while a single building upgrade is more localized — when genuinely torn between two similarly-weighted options, leaning toward research is a reasonable default tiebreaker.
Don't overthink small decisions
This kind of prioritization matters most when speedups are genuinely scarce and the choice is close — if you have a comfortable surplus of speedups, this distinction matters far less, and it's fine to simply keep both queues moving without careful optimization every time.
