Database File Free Space
If a data file runs out of free space, it attempts to grow (assuming autogrowth is enabled). Even with an excellent autogrowth strategy, it is prudent to manually grow files since this can be done in a more controlled manner (e.g., at a suitable time).
Conversely, if a data file has excessive free space, this is potentially a waste of storage, which could be reclaimed by shrinking the data file.
Maintain 5-10% free space in all data files and grow them manually.
Any suggestion from Aireforge should be thoroughly tested before being implemented into production.