Best power supply for a BLDC motor; linear or SMPS?
What really matters in this power supply us the ability to sink current, if the servo regenerates energy, which happens quite often. In fact best is a transformer + rectifier which a huge capacitor.

But on the other hand, in my practice most people ignore that and usually no damage is done. I would say that 99% of cases use smps, as they are cheap, small and available, and it works perfectly. Just need to be sure your servo rated voltage is significantly higher than the smps output, so if the voltage risea due to regeneration, no damage is done.