Do you mean keyframing all the hand poses within the Action? Yeah, that can be tedious. When I was doing development work for
Harvey Street Kids, I tried to create a 'standardized' rig that could be repurposed for each character, and one of the features was a hand setup that had something like 50 different hand poses built in. Took forever to set up, and in practice, animating the hand was cumbersome. Specifically, there were just too many drawings to scroll through with a single bone dial. So then I tried breaking the hand control into multiple hand controls to switch between groups of hand poses (i.e., palm, palm side, back, back side, finger tips, etc.) That required less scrolling and the sensible structure made it a lot easier to animate...but it was a pain to update whenever an animator asked me to add another hand drawing, because I'd have create multiple views for every new hand or upset the structure. I think in the end, I just added a 'specials' category into which the animator could add whatever shot-specific hand drawing they wanted, and I would later add that drawing to 'special' category in the master rig without upsetting the 'standard' hand structure. This way, the new drawing would be available to the next animate using the rig. Still, a pain in the butt since by that time I'd already moved on to a different project.
If I took a similar approach
today, I wouldn't bother with the Smart Bone. Instead, I'd set up a
Layer Shortcuts button to select the hand switch, and just use the Switch Selection window to scrub through the hand poses. I like this method for mouths, eyes, and sometimes hands; it's fast and easy to set up and animate with, easier to scrub a lot of drawings quickly, and no Smart Bone is required. (You've probably seen this but I posted a demo video here:
Introduction To Layer Shortcuts.)
In later shows (
Boss Baby specifically,) I came up with a standard hand rig that used fewer drawings because each hand drawing was fully poseable to each fingers using only Smart Bone Actions and no hand bones. That system took a long time to set up too but it was really easy to animate, looked great, and the setup was re-usable between different characters. (Well, for characters with similar 'kid' hands anyway. Then, along came Victor, who came up with the brilliant idea to use a Smart Warp to globally reshape my setup into 'grown up' hands.)
Unfortunately, this system completely fails with Moho 13 because of the Actions ID issue. Another reason I stopped using Moho 13.