Okay. When we talk about political background, we usually mean that one has held a position with political decision-making ability, rather than an auxiliary position. Judging from Gao's resume, he has worked in relevant administrative work, but not a position with political decision-making ability.
Positions with political decision-making ability usually refer to positions with decision-making power within a certain range. For example: village head, town head, mayor, governor, or department head of a professional political institution.
This may be different from your understanding.
Similar to him, there is another person who has been popular recently. Shen Yi
Interestingly, there are some news commentators in China with military backgrounds who also have a 50%:50% credibility rating on Chinese social media.
=============================================
Regarding the J-35, we have the simplest evidence:
Recently, China is preparing for the "9.3 Military Parade".
In order to gather enough J-35s to participate in the parade, SAC brought all the J-35 prototypes with pitot tubes to participate in the parade. If they had enough J-35s, they would not have brought out the prototypes.