Why do you use "mesh from curve/meta/surf/text", instead of applying the subdivision please?
This video is GOLD, because it contains some valuable information about facial features and sculpt technique, like the 3 wrinkle steps! Great!
Now, a question: in the video at the time stamp 31:58s, instead of applying the subdivision, you used "mesh from curve/meta/surf/text".
Yes, the end results look the same, however, the end results may not tell the full story, since these two operations are identical only if the two algorithms behind Blender are exactly the same.
According to the user manual:
The official user manual has never said that the two operations are exactly identical. So are you 100% sure that: mesh from curve/meta/surf/text = applying the subdivision ?
If it is not exactly identical, then we could be running a risk to ruin the sculpt work, though the risk may be low.