This is a somewhat embarrassing issue.
The Warhawk Special Research Group was formed simply because Zhao Yi had made a request, and the Aviation Group approved the team's establishment to specifically develop the Warhawk-1 fighter jet. However, the specific type of fighter jet was only vaguely defined as a 'fifth-generation aircraft.' There had been no discussion about specific design requirements or features that the designed aircraft needed to have.
The main reason was...
Most people within the Aviation Group were not optimistic about Zhao Yi's team being able to quickly design and finish the Warhawk-1 fighter jet. Even if it could eventually be completed, it would take at least a few years. They thought it would not be too late to discuss the design once there was some progress. However, the Warhawk-1 was quickly designed and passed acceptance checks without any issues found. Making even the simplest modification to the original design seemed like a desecration of it.