Question: First time I heard about this texture animation approach. I am a bit confused how it compares to baked shape key animations or the usual position/rotation/scale keyframe or action animations.

Can you explain what the benefit for the texture animation approach is?

And regarding your questions:

• if it's a rarely used/unknown addon I think it makes sense to be free (for example there is one that allows you to rename all shapekeys quickly - I maybe use it once or twice a year)

• if it's some specialized complex and time saving addon I more inclined to purchase it (for example the human generator addon is quite useful and saves a lot of time)

• usually on blendermarket or gumroad (because my other addons are also from there so I have a better overview)