The fact that Dorico will have separately editable note onset, durations and velocities stored within each notated note is good news, since this provides the most important building block not only for whatever performance editing tools come online later, but also for renotating / retranscribing the visible music notation.
See : Midi files and also Performance settings - Dorico - Steinberg Forums
I’ve always associated the term “Humanize Playback” with tools which on their own make micro adjustments to performance attributes like timings, dynamics or tempo changes using some set of controlled random variables in order to simulate “live performance”. I’ve never really cared much for this approach, since it doesn’t effectively capture human phrasing at all.
Another approach; Logic’s “Groove Templates”, DP’s “Groove Quantize” and Pro Tool’s “Feel Injector” (all based on work by acoustic researcher Ernest Cholakis) allow specific performance attributes from one track to be copied to another (and which can also include some amount of mild randomization, or can leave existing notes or phrases already within a particular tolerance alone to “humanize” what would otherwise be an exact performance copy.)
The net effect is much more realistic than simply randomizing performance attributes, but is perhaps more ideally suited for music centered around a rhythm section than for orchestral phrasing.
There is also “on the fly” randomization of playback nuance built into some sample libraries, which people seem to like.
However, it seems that the discussion focus here is on editing tools which can filter for specific performance data types within specific ranges, dynamics, octaves or locations etc. and allow quick editing to these selections.
I had to look up C_brains, which I now know is a Cubase MIDI editor for iOS Lemur. Here is a link for those not familiar:
http://www.midikinetics.com/c_brains.html
C_brains is a testament to how talented, third party developers can add tremendous productivity and value to an existing program if the proper scripting hooks are made available to them.