Roles are communication shortcuts
Wash, Carry & place, Flexible, and room owner are not official character classes. They simply make responsibilities easy to say. A player can change roles whenever the remaining work changes. The point is to reduce duplicate actions and ambiguous handoffs, not to lock the group into a permanent team composition.
Handoffs need destinations
An object pile without labels creates a second mystery. When a player finds a likely cross-room item, say what it is and where it probably belongs, then leave it at the agreed handoff point. The receiving room owner confirms the placement and reports whether progress changed.
Progress checking is a real job
One player should periodically compare finished rooms, unresolved items, and missed-dirt reports. This can rotate between players and does not require a special ability. The task planner helps by showing per-player effort and first tasks without sending player names or notes away from the browser.