So I just picked up a 2017 Fathom 1 29er for my friend and after searching youtube and googling everything I could, I learned that it was highly likely that I could extend the fork from 100mm to 120mm while also gaining a little bit in they head angle.

I found youtube videos for all EXCEPT the Axon. All other Suntour air forks adjust by moving a roll pin in the air side shaft. The Axon however, is even easier. See the parts breakdown here:
http://www.srsuntour-cycling.com/fil...100,80-(1).PDF

The little spacers (item 9g) determine travel.
4 spacers = 80mm
2 spacers = 100mm
0 spacers = 120mm
Of course you could set the travel anywhere in between since each spacer is 10mm.

All you need is:
10mm socket
5mm allen
adjustable wrench
soft tip hammer/mallet


Total time = 15min
Removal of the fork from the bike is not required.

While this video is for the Epicon, they do touch on the Axon.
https://www.youtube.com/watch?v=n5BgLgXHtSM&t=203s

Hope this helps someone!