If you offset a PLINE only once (without curly brackets around it), the option for making it a pocket will hold.  However, if you offset it multiple times (which requires curly brackets around each instance), the PLINE loses the pocket option you tried to apply.  Though I understand how it is currently programmed (explained by MV support, illustrated by me below), as a user, I expect the PLINE to keep its properties, no matter how many times I offset it.  There is no logical reason I would want the PLINE, for which I have the pocket option turned on, to stop pocketing if I offset it more than once.