I think it's fine to use the IC ground here. Again, use moderation with the star grounding approach. It gets unwieldy fast. Any common power elements (the IC, a neighboring IC with compatible power demands, and their decoupling caps) can absolutely share a little ground plane. Just don't run a single trace from one to the next. That invites the ground trace to raise above 0v between points, offsetting the reference level for anything in between. If you can't use a plane, use several traces that meet at a single point and trunk back to the main ground.