v2.1.0 on 2026-10-01: PCHEM modifications

Changes and corrections in preparation for GCM release v11.11.0

What's Changed

• Updates for new GCM v11.11.0 Release by @sdrabenh in #324
• Sync develop into main by @sdrabenh in #325

Full Changelog: v2.0.0...v2.1.0