This is from the jw org online about pioneers
The term “pioneer” often refers to those who explore new territories and open up a way for others to follow. Jesus was a pioneer of sorts, having been sent to the earth to perform a life-giving ministry and to open the way to salvation. (Matthew 20:28) Today, his followers are imitating him by spending as much time as possible ‘making disciples.’ (Matthew 28:19, 20) Some have been able to take up what we call the pioneer service.
A pioneer is a full-time evangelizer. All of Jehovah’s Witnesses are publishers of the good news. However, some have organized their life to serve as regular pioneers, spending 70 hours each month in the preaching work. To do this, many limit their secular work to part-time
Notice the last section which suggests that there are some that continue to work full time.
At 70 hours a month, it equates to 16 hours a week. (66 hours a week - FT job and pioneering). I thought this would not be unusual for people in the US who have two jobs, a job with lots of overtime or a secular job requiring this.
Just as a side point I found the statements by the org interesting and a bit more honest than usual, although still obscure to a degree. They basically admit that they are not using the word 'pioneer' in its normal meaning.