My two cents:
I think accuracy is closely related to a well-developed body map, combined with a well-developed keyboard map. This, in turn, is related to the issue of playing without looking at the keyborad (i.e. sightreading, or playing blindfolded, or looking dreamily at the clouds while the audience is admiring the performer.
Developing a body map takes a lot of time, but is ultimately indispensable. Juggling (Bernhard's favorite) is a great way, and so is any activity as long as one is paying attention. The same thing goes for developing a keyboard map.
Just to make sure: A keyboard map means knowing what the distance is between, for example, 3 notes, an octave or a jump from C1 to C4. A body map means knowing how to move so that these distances are accurately covered.
Silent practice is, in a way, an isolated exercise. We know what Bernhard thinks about isolated exercises, and I can only assume that it is the same reasons why he doesn't advocate too much silent practice. On the other hand, he did describe the potential benefits in earlier posts (links above), so, as with any such exercise, personal affinity should decide over using or not using it.
I do like silent practice for another reason. It has to do with focus. It is impossible, and in my opinion counterproductive, to focus on a single issue (e.g. how the fingers move) while playing a piece or practicing. The reason is that focusing (concentrating on) at the same time means neglecting everything else. So, by focusing on one aspect, one easily misses what might be going wrong somewhere else. Perhaps the problem with the fingers is not in the fingers, but in how I use my shoulders, so focussing on my fingers will not allow me to solve the problem. I may even come up with "solutions" that will introduce more problems. One really has to take everything in simultaneously to make good progress.
Silent practice takes away sound. Therefore, I don't have to ignore sound, because it is not there in the first place. Focussing now is no longer an exercise in cutting out as much information as possible, which might be dangerous as just explained. Instead, one can take in all the information and process it much more easily.
So, there are aspects that can be practiced well in an isolated fashion. Most of them can actually be practiced away from the piano.