When multiple bones have transform constraints targeting the same parent, the values for those transform constraints all appear on the parent in the timeline. Ideally, when selecting a child bone, we would also be able to see its corresponding constraint values on the timeline, making it easier to adjust each one individually.
If you get timelines for all constraints that have the selected bone as a target, it could be a lot of timelines. We group the constraint under the target, making for a single place it appears. If it also appears under constrained bones, there's a question of what happens when both are selected. It's a bit messy. Probably you should lock the dopesheet instead.
What I’d like is that when selecting a slider, the corresponding parameters can be seen directly on the timeline, instead of having to select a bone first in order to see all the parameters. Otherwise, when there are many slider constraints, it becomes quite frustrating.
The video for this didn't make sense. You selected a slider with no bone and then what? What selecting a slider you want to see keys? You should. Maybe they were below your bones, off screen?
Currently, slider constraints tend to work as 0–100, meaning a minimum-to-maximum two-point parameter.
What is 0-100? Mix? Frame is not 0-100, it's 0 to animation duration.
However, in actual production, there is another more common use case: a three-point parameter. For example, with eyes, it might be “wider open – default – closed.” For eyebrow position, it might be “higher – default – lower.”
OK, but you only stated facts, I don't know what point you are trying to make here?
You can store any number of frames in a slider animation. You can store poses or animations and use them like "morphs". For example, wide open eye to normal could be frames 0-10, normal to closed 20-30. You can repeat a pose for a different transition, eg normal to angry 40-50. If you have 3 where one is in the middle, you don't need to repeat a pose, since you can do A<->B<->C. That could be all in the same slider, or in multiple. Then you can key the slider frame to show poses, or you can key the slider frame with interpolation to change the frame over time, so you transition from frame 20-30 to "play" normal to closed.
If you mean you want to mix 3 poses, you could use 3 sliders.
This also affects adjusting the progress value of slider constraints. If we want to batch-reset them to their default values — which are not necessarily 0 — or batch-edit them, it can become quite troublesome.
As Misaki mentioned, the favor tool can move to (or toward, or away) from the setup pose. You can also select constraints in setup mode, ctrl+C to copy the constraint settings, then paste in animate mode. You can create an animation and use it to store poses, then you can go to that animation and copy keys or constraint settings.
