The ETA 2824 is widely serviceable
Movement familiarity can make diagnosis and service more predictable than on proprietary or highly complicated calibers.
Crowns, crystals and bracelets are still model-specific
A common movement does not make a proprietary crown, crystal or dial easier to source.
Running fast or slow is only one clue
Poor rate can be regulation, magnetism, amplitude, wear or service condition. The movement must be evaluated rather than tuned blindly.
Previous repairs can change what the watch needs
Previous replacement parts, worn rotors, calendar damage and over-lubrication can change what a routine service becomes.