Most fabricators will have a hold down force limit. Typically, this is dealt with by breaking the one hold down location into two or more to stay under the fabricators limit (usually this is done by the fabricator and not by the designer).
Yes, there is a limit on the total hold down force. If the force is too high, meaning too many strands are deflected, you can suspend the beam from the strands and that is not a good situation (beam wants to raise up off the bed which is a major safety concern).
General standard practice is to design with straight strands and use debonding to control stresses at the ends. Using debonding tends to reduce end stress cracks more than draping. If a debonding pattern is unattainable based on the limits of AASHTO or the specifications, drape the minimum number of strands required to meet the criteria.