Of course, this is different from the direct undergraduate course! Direct undergraduate education, which is full-time undergraduate education, is the most recognized education. I took part in the national unified college entrance examination and went to college! (Of course, there are also undergraduate courses, but it is 3+2, three years and two years. It is also a full-time undergraduate recognized by the state)
That 1+3 2+2 is generally used by on-the-job personnel to promote or evaluate their professional titles (only useful for state-owned enterprises, institutions and national civil servants), and private enterprises do not recognize it. You can take the exam even after graduating from primary school. As long as you pay the tuition, you will be able to take the exam. Check online if you don't believe me. Universities like Tsinghua Peking University issue such certificates, as long as you pay the money.