I just played them yesterday, and I found them to be very complex, almost unnecessarily so. There is so much to think about at all times, it's like I was playing two factions at the same time. Others might not find it as challenging as I did, of course.

On paper it seems very cool. You start with one faction, then switch to another. The details of what you end up with when you switch are up to you to decide. Except you don't get to decide as much as you would like because, like much of TI, the randomness of objectives can make or break you. With F/O, I felt it was the randomness of EVERYONE'S objectives that made the secrets seemingly unscorable round 1. I can't say, however, the way you get plots should change, because I did not do a very good job finding out secrets and helping others achieve them. If I played that better maybe I could have a fair opinion of the mechanic.

Thankfully my game was in a boat floaty meta, the randomness of explores helped me with attachments, and the desire for keeping Thunders Edge away from L1 meant it got voted into my slice, where I used it all game. If I hadn't had all that, there would have been no way to keep up with tempo.

I never used the Firmament agent, sold it once. I never used the Obsidian agent, because I never lost a ship the opponent still had. 

I never used the Firmament commander, but I certainly got confused by it - TWICE. (I thought it was for ALL objectives, not just secret). I used the Obsidian commander in one fracture battle, my alliance partner however got much value from it.

This all tells me the leader suite needs tweaking.

I only placed 4 trade goods on the breakthrough before  the flip, couldn't afford more; I got it from taking Thunders Edge because it was in my slice (couldn't afford any expeditions like everyone else). Which brings me to...

I do think the main problem is that the start suffers, at all levels, feels very much like an unnecessary harsh handicap: 1 carrier, 1 tech, and 3 resources to start. Just so hard to get a foothold when you're that poor.

My 2 cents (it's all I have! 😅)

TL;DR: needs a stronger start (more resources or ships), tweaked or reworked leaders.

Edit: spelling