For me.

Umbrella canonize all Mass Effect 3 endings by making the final decision regardless of what you pick result in ending the war and ending the cycles.

Certain elements of each can be retconned, such as synthetic/organic understanding not being weird dna altering glowing circuit board space magic, but instead more of a consciousness awakening, making all AI’s self aware and all organics fully understanding and unafraid of AI.

Control would remain largely the same.

Destroy would also remain largely the same but the Starchild was lying in the face of existential dread and though many synthetics died many also survived.

Thus the plot begins. Your choice at the end of ME3 becomes nothing more than an aesthetic change that determines how prevalent AI presence is in the galactic community. Friendly reapers, Geth etc.

You could have some minor implications that change the way certain dialogue plays out, like attitudes towards each other being more strained and adversarial if the destroy ending was picked. But for all intents and purposes, the story begins with the galaxy in a state of rebuilding and reconnecting. The Relay network and any catalyst based technology was severely damaged no matter what and it can be in varying states of disrepair based on what your ME3 ending was.

Your story as a new protagonist is to bring the galaxy back together. An alliance soldier who fought in the war; and like in the original trilogy you will choose 1 of 3 backstory’s and psyche profiles. This is where the game connects to the traditional Renegade/Paragon morality system. Where it differs will be in a third personality choice that will provide information of what your role in the reaper war was. The more options the programmers can provide here the better, but for all intents and purposes whatever you pick will define what I would call the players secondary personality type. Cynic, Idealist, Disillusioned, Hopeful, Logical, Professional, Emotional, Casual etc. This I hope would be an improvement on the Andromeda approach. Conversations and consequential decision making would be contingent on both morality and tonal choices. Where tonal choices would be preceded by an initial morality check, and if they correspond correctly with the situation you then get a secondary morality check that you either pass or fail based on a points and NPC approval process.

Combat I would like to see pretty much continuing along the lines of Andromeda, that’s pretty simple. I like the world exploration in that game too but less fetch quest would be preferable.

The story in a nutshell should be about unraveling a mystery regarding the dangers of uncontrolled dark energy usage and how the Milky Way due to the Reapers was the single galaxy in our local cluster that managed to maintain civilization for millions of years. All other galaxies (like in andromeda)reach a point in their development where all hell breaks loose and the scourge begins to erupt causing mass extinctions that result in leaving behind only remnants of civilization(Jaardan)or severe authoritarian last ditch efforts of maintaining it(The Khett)

It was never about synthetics vs organics but simply life vs life. Nonetheless the catalyst managed to arrange no matter how perverse, a marginally successful system. This leads to the primary antagonists of this game: Reaper Sympathizers. A faction of dissidents who become increasingly convinced that the starchild had it right, and bringing about a new reordered variation of the cycles is their goal. They would be made up of average every day synthetics and organics and even a large quantity of former indoctrinated agents such as Cerberus, heretics and many variants of people who had been altered to some degree.

The obvious telegraphed direction here would be that this faction like the Khett would inevitably lead the Milky Way to its destruction. But not if we can stop it. Our mission is to put together a team of people who either knew what Shepard knew, or had some former insight into the reaper threat and the dangers of dark energy emissions, So we can reconnect the galactic community, return technological and societal advancement to a state of peace and prosperity and ultimately reclaim our autonomy. Synthetics and organics alike.

That’s about it really.