1. Please have more real choices rather than flow charts. More viable tech paths. More viable unit paths. More viable everything. The framework is all there in beyond earth, but it NEEDS to be tweaked so there's a lot more viability.
2. Please god have the new diplomacy system be good. All these games have AWFUL diplomacy systems, and it's a shame because it's really the most interesting potential thing, especially in a good single player system. The most creative strides i've seen in that area are Endless Legend which has a resource for diplomatic actions (which while poorly implemented has a ton of potential to allow cool things such as forcing wars or peace, or great interactions with espionage) or solium infernum (which is a mess everywhere else).
3. Touching on the last one, Beyond earth almost has the best espionage system in a 4x game to date, as most of them are extremely shallow behind the scenes dice rolling. Flesh it out, get rid of stupid techs that just make ALL the cool stuff impossible, and make it something everyone talks about.
4. REALIZE YOUR GAMES AROUND ABOUT LEVERAGING RESOURCES. I don't get how many times they have to do this. Civ V launches. There's basically one strat. Many expansions later I can go hard core religion, and turn it into a military, science, econ, or cultural victory. If i want to rush culture, I can, and then finish with that or spread out into another victory. Science always lets you tech hard if you get the space and crush people with new toys. Military of course also has quick and instant payoffs when balanced right.
Beyond earth is heavily lacking in this. If i go heavy espionage/diplomacy, 1. make that a thing, and 2. make it pay off. Let me leverage a victory or a serious advantage from it. We've got the cool toys at the end of the tech tree for espionage (worm attack and stuff) but it's not nearly viable.
If i go heavy sat coverage, let me turn that into something.
If I want to wonder spam, let that turn into something (there's at least the culture spam thing sorta).
There's so many potential paths, but in practice the numbers/features don't work out, and it's SUPER frustrating in BE simply because they don't need to tear anything apart or start from square one or even introduce new mechanics. They just need to do a numbers balance.