This has been an open ask since 2024 (see "Save Layer Collapse State") but it's still unresolved, so I wanted to bring it back up with a concrete use case.
On multi-discipline data center electrical sets, our layer lists get long fast — power, lighting, low-voltage, fire alarm, each with sub-groups. Layer groups with collapse/expand are great for keeping that organized, but the collapsed state doesn't save — every time the file is closed and reopened, the whole tree springs back open. That means re-collapsing the same groups every session, which defeats the purpose of organizing them in the first place.
Revu already handles this correctly for Bookmarks, which do remember their collapsed/expanded state between sessions. Layers should behave the same way — even storing collapse state per layer group directly in the PDF (or in local Revu settings) would solve it.
This would be a meaningful quality-of-life fix for anyone managing large, layer-heavy PDFs — VDC/BIM coordinators on multi-discipline projects especially.
