Just exactly how were they proposing to cap your return? A safe or note with a cap is designed to cap the price you pay for shares, not cap your return.
Safes or notes without a cap are rare
Safes or notes without a cap are rare
As an angel in that scenario, you’re investing with the risk profile of a very, very early company but the return profile of a later investor.
It also bypasses the sometimes arcane and high friction step of trying to value an early stage company.
Note that access isn't very useful if the returns aren't there (see the capped return point).