Nathan,
I have some detailed information about borrowing.
By default PTC sends out 2 license packs, standard.txt and non-standard.txt files.
Standard.txt file is basically downward compatible which means that one can work with any release of Pro/ENGINEER right from Wildfire 5.0 to Pro/ENGINEER 2001.
Non-standard license file is basically a borrow license file. This borrow functionality has been introduced since Wildfire 2.0 and hence if this license is used then one can work only till Wildfire 2.0(WF5.0, WF4.0, WF3.0, WF2.0).
So one has to decide based upon their requirement as to which license they want to use.
In your case, you need to use latest datecode release of Wildfire 2.0 or any datecode release greater that M160 in order to use the borrow functionality as this functionality has been introduced during these datecode releases.
By default you can borrow Wildfire 2.0 license for a max of 5days but by setting an Environment Variable, LM_BORROW_DURATION to 10, one can extend the borrow period to 10days.(including 0).
You can refer to TPI-128654
~Ash..