For equity investments, control of when and on what terms a property is sold is down to the investors. This is done through a Shareholders' Resolution.
Each rental property is listed with a fixed term in mind. Around 2-3 months before the expiry of the term, the Board of the SPV will assess the market and make a proposal to investors explaining the proposed exit route or term extension. Investors will then have the opportunity to vote if they want to support the resolution or not. There is a 14 day fixed period for responding, with abstentions being deemed to agree to the resolution. This is designed to avoid situations where people are holding up an exit if they are unavailable (or uninterested!). If 75% of investors agree to the resolution then it will be acted upon accordingly.