FA, for me, have a big problem with adjacency bonuses :
They are mandatory OR useless. They are never an option or a choice. (Except for the radar and maybe the air factory).
For example, the mexes upgrades.
If you want to be really be cost effective, there is only ONE way to tech from T2 to T3. And it pass by making mex storage.
They must be done at tier 2, because, well, the maths prove it, but what does it add to the game ?
For me it make the game more complex and more difficult to understand for new player, without adding any depth in the game.
You have to do it, you have to do it at a specific time with a specific amount of engys, or you are doing it wrong. They is not other good justification to it.
One of the goal of FAF was to bring back players, but also bring NEW players to it. The economy is already enough complicated to
understand and master (after 3 years, some players are still not able to do it).
I see a lot of new players connecting energy with mexes, because it's logical : You see a nice connection line... But nothing with storage !?
I'm all for making the game less difficult to play, but deeper strategy-wise.
So for me, that's meaning removing all the things that don't bring more choices in the game... So, removing these T2 mass storage bonuses, and balance it otherwise (a 2.5 tier upgrade ? Redo the cost/time ? Making mass fab a replacement AND a choice for them ?)
Same with T2/T3 arty. These kind of connections should have more boost too. The radar is a perfect exemple of that : It's a choice, the bonus is nice, but it costs you 4 pgens.
For t2 arty, the reload should really be increased.
I know a lot of (old) players will not agree with me, but try to thing about what it really bring to the game...