Adobe has released an official document containing tips to maximize Lightroom performance. I found this section pretty revealing:
Order of Develop operations
The best order of Develop operations to increase performance is as follows:
Note: Performing spot healing first improves the accuracy of the spot healing, and ensures the boundaries of the healed areas match the spot location.
Order of Develop operations
The best order of Develop operations to increase performance is as follows:
- Spot healing.
- Geometry corrections, such as Lens Correction profiles and Manual corrections, including keystone corrections using the Vertical slider.
- Global non-detail corrections, such as Exposure and White Balance. These corrections can also be done first if desired.
- Local corrections, such as Gradient Filter and Adjustment Brush strokes.
- Detail corrections, such as Noise Reduction and Sharpening.
Note: Performing spot healing first improves the accuracy of the spot healing, and ensures the boundaries of the healed areas match the spot location.