The most important part to add from the GM's guide is the archetypes for the villains. Please add these to the main Update files for herolab 3e.
The GM's guide may have other things to add but can you please start with the archetypes, they are merely an extension of the core book archetypes. If it is possible, the GM's kit archetype build options would be awesome.
Basically load the archetype as stated, and then each has different variation options so you might have Power house with 3 variations, same basic character but slight tiny differences.
Anyone up for doing something like that? If not, please consider the addition of the Villain Archetypes