Upon further research on the checkbox issue, I just realized that {AS}->{value} is where you can control the option

In the same PDF file that I worked in above instance, there is another kind of check box in the dictionary that is using indirectObject

which points to a parent dictionary which has {AS}->{value}. In this instance {AS}->{value} was set "Off" initially but I had to use {D}->{value} which is inside of the same parent dictionary to set {AS}->{value} to turn check box on,in my case, it is "Yes_2", that is {AS}-{value}="Yes_2"