Added finger flexion/extension controls, and got a bonus posing feature for free by selecting all the controls and dragging them left/right/up/down from different viewpoints. This causes them to move at different speeds - which I normally find to be a hindrance when manipulating items - but in this particular case it turns out to be “handy”.
Also added IK damping thanks to this tutorial (which especially makes the fingers easier to control when at full extension), IK/FK switches, and general model/rig improvements.
The IK/FK switching gave me some troubles, which I ultimately reported as a bug - only to be informed by Brecht (within 2 hours of me submitting the report no less) that it was a cyclic dependency issue - for which he proceeded to prescribe directions to locate the error (which alerted me to a whole cascade of such errors), along with a snippet of code that made them all go away.
How’s that for customer service! 