Only 3.8% growth is actually needed to reach the economic goal....

Xi specifically said he would double GDP per capita by 2035 (15 years) but this is based on NOMINAL GDP (which includes inflation) not real GDP. By examining Chinese economic data 2006-2019 we see that a doubling of per capita GDP only results in a real GDP growth of 56-76% (varies with inflation, exchange rates, etc). This means Xi would only need about 3.8% annual real GDP growth to meet this target by 2035 (if inflation remains 2-3%). The CCP could makeup any shortfalls by increasing inflation by a small fraction to make up the difference.

(disclaimer: I'm not a professional economist)