A SAFE avoids negotiating a valuation, which is why early rounds use them. Nobody argues about what the company is worth because the question is deferred.
It is deferred, not removed. Stacked SAFEs with different caps and discounts all convert at the priced round, and founders regularly discover they have sold more of the company than they thought.
Model the conversion before signing the next one. If the combined dilution is beyond what you intended, a priced round now may be cheaper than three more SAFEs.

