Is Child Status Protection Act valid for H4 child

[DKP]

My son,  H4 dependent visa in 2nd year of college, is turning 21 next year in November, 2018.  Is the anything that can be done to keep the dependent in the green card process.  I-140 cleared in 2011 and changed job recently.  Applying for new labor, I-140 under EB2 Category.  I am not sure if H1B visa holder can do anything to protect his child from ageing out to 21 with Child Status Protection Act.  Is converting him to F1 is the only option.  Please advise.

DKP