Can a brand-new, unassigned volunteer see currently-needed positions on a template (before a plan exists) and self-select one to be placed on a team?

Answer

Confirmed: build a Registrations signup with a selection type per open position/time, set each selection type's capacity to match open spots, and build an automation directly from the selection type to add registrants to the matching Services team/position (no separate People list needed). Capacity isn't live-synced with Services Needed Positions, and placement isn't instant.