I would like to be able insert a base feature then use the edit face by selecting a pre-existing face on a solid. Right now the workflow is to create a solid inside the base feature or convert to DM by right clicking in the timeline which collapses all the history of that object leaving previous features, fillets... inaccessible.
I can use a work around by creating a solid (with features), then inserting a base feature, while in base feature sketch on desired face, project geometry of the face into the new sketch, make a patch from the resulting sketch, perform edit face on the patch, exit base feature, and then use replace face to replace the original face of the solid.
Not exactly a pretty workflow but it does demonstrate that the functionality could be implemented I believe.
See my work around file here: https://a360.co/2Io4Gy6