Ideally...Larian implements 5e RAW except for necessary changes for a video game adaptation, and then adds various toggle options. Doing this could also massively boost replayability by providing essentially entirely new combat experiences.
- Cantrip surfaces: on/off
- Shove (and other universal actions): action/bonus action
- Jump: BA w/disengage / BA without Disengage / Free action
- High/Low Ground: Advantage / +2 / no bonus
- Backstab: Advantage / +2 / no bonus
- Food: In-combat healing / Req for Resting
etc
I'm not sure, but my guess is that such options would have too many consequences on the AI.
I'm not sure options can change the core game's mechanics.
Most options in WOTR, a game always praised for his number of options feels very "neutral" on the AI behavior.
Food x1.5 for long rest / x1.5 damages / weight effects ON/OFF / prepare spells only at camp / ... even random encounter ON/OFF seems to me like options that can more reasonably be expected.
That's fair and an important consideration.
For some of these changes, you could simply have the AI weigh toggle options the same. E.g., High Ground Advantage vs +2 bonus. It'd make the AI act a bit suboptimally in some cases, but that's fine. But for others (e.g., Action vs BA Shove. High Ground bonus vs no bonus) the AI would need to be able to make use of each case individually.
I have no idea how hard it is to create different versions of enemy AI. The difficulty and worth of this task is up to Larian to decide, adding these options would make many players happier though.