Ok, I know this has to be a pretty simple thing but I'm finding myself a little stumped. In the hip file attached I've got a simple test sim with packed RBD and constraint network. I'm grouping points and making them active to create a very specific shape in how it breaks apart initially.

So far so good, but at some stage in the sim I'd like to add other groups to the active state to have it fall apart in stages. I know this is a task for a sop solver, but everything I've tried on this so far doesn't yield anything. Much appreciate any advice and help on this!

I didn't have time to set this up in your scene, but I did set up a simple scene for you to demonstrate how to use an animated active value. I have a solver sop being used to accumulate the active value, that you can try enabling and disabling. Notice that if you disable it, the active value doesn't get retained, and as the group loses its active value, the pieces freeze. If we have the solver sop enabled, the active value remains if it is ever inherited. Hopefully something like this helps.

Super helpful, thanks! I'm not clear on why the for-loop is needed, promoting the point color attribute to detail and back again. Thanks again

For what it's worth here's the fixed .hip file, Thanks Midassilver for the tips. Since I'm setting my active value with bounded grouping I didn't need to use the solver sop to accumulate color

Cool, glad you figured it out. For your reference, the purpose of the for each sop was to get access to the individual shards. Then when we promote the color it receives from point to detail with method maximum, the moment a point on the shard becomes red, the entire shard becomes red. This way, we set the active value instantly properly. Then we promote the color back down to point again before the sim.