Voting / investor consent may be carried out by each individual investor, or the group of investors may agree to proxy this activity to a single investor in the syndicate (simpler). In most cases, the group of investors will agree to proxy this activity to a single investor in the syndicate (the Syndicate Lead). However, voting / investor consent may be carried out by each individual investor, or proxied to someone else (eg. the founder or Chairperson).
In general, all the investors in the syndicate are entitled to exercise their pre-emption rights, and can do so directly or via another SPV structure in future rounds.
You can choose to control pre-emption and information rights only if you are a regulated fund manager.