Bravo for the rejuvenated script & please keep the fantastic work up. Kudos.

I tested Flightnetwork and there are unfortunately 2 errors:
1 .I believe that there's slight mistake in parameter that's left out and hence it's not pricing correctly. I have PMed you the typo and hopefully the minor issue can be fixed easily.
2. The FN link is not enabled for multi city search, even though FN does support multi city.

Btw, Hop2, Wow fare and Ovago etc.. are actually just affiliates that have subscribed to the exactly same pricing engine..(whose name I unfortunately dont remember at moment). It's more like providing one's css and domain name and then it all points to exactly same thing in the backed.. Moreover they yield exact same dollar price & exact same flight options. In my opinion, these are simply clutter and occupy unnecessary screen real estate, developer time and adds no additional value. It might be better to just keep any one of them & discard the rest. Sample results can be seen below for analysis.
https://ibb.co/SxVjHc8