How to animate on original controlrig animation layer after creating additive layer?

When I create an additive layer after baking my animation clips to a control rig, all animation and all keys made by manipulating the control curves go onto the last layer made. How can I choose which layer takes priority and have the keys set there?

For example, I want to 0 out the finger controls on the original animation layer. Selecting all the controls in the viewport and setting rotations to 0 doesnt work, since the transforms are all referenced from the additive animation layer. I select all the controls under the base layer in the sequencer and 0 those out, but that doesnt work either since it still is just ‘selecting’ the controls and those controls are now only affecting the additive layer. I have to manually and painfully go into the base layer, uncollapse each finger control, and set the three values all to 0.

So I’m wondering how I can:

Tell my controls to start modifying the original base animation layer, not the additive layer

or

easily modify control values in the base layer without having to manually input values into the sequencer