The pooled QOF structure is genuinely different from a direct deal in ways that bite people exactly like this. Most subscription docs I have reviewed do not give you a clean redemption right tied to deployment timelines, full stop. What they usually have is a gate provision, meaning you can request redemption but the manager can defer it, sometimes up to 12 months, if honoring it would require liquidating assets or disrupting the fund. If deployment hasn't happened yet there are no assets to liquidate so the gate language becomes almost meaningless as a lever. What you should actually be looking for in your docs is whether there is a "key person" clause or an investment period termination right, because those are the provisions that sometimes give an LP committee or a supermajority of capital the ability to halt new commitments or trigger a wind-down if the manager misses a stated milestone. That is a real lever, but it requires other LPs to act with you, not something you can pull alone.
On the Q3 timeline, I would push back on the framing that sellers control everything. Managers who are actually under contract on a deal know their projected close date to within two or three weeks, and they can say that without disclosing confidential terms. "Q3" as a full answer to a direct question from a subscribed investor in June is a manager who either does not have a deal under contract yet or does not want to tell you why the one they had fell through. I had a similar situation in a smaller syndication in Columbus in 2021, not a QOF but same dynamic, and when I started asking for the specific milestone the money was tied to rather than a quarter, the manager eventually admitted the seller had gone back to market. You are not being unreasonable. You are asking a question that a competent manager should be able to answer more precisely than that.