Renter (rate)
Renter is a rate, not a role. It is a commonly-used label for a member rate with low or zero recurring dues and a higher per-hour usage charge — the shape of deal a syndicate offers members who fly or use the asset occasionally without taking on an equity stake.
A member on the renter rate is still a member of the syndicate. Their role is member; what differs is the billing scheme they are assigned to. Documentation that uses the word renter always positions it as a rate label.
Syndicates can run any number of named rates side by side — Equity, Renter, Founder, Instructor — and assign each member to one.