Because the warfare mod IMO covers too much ground (also changing the decision making of squads, respawn behavior etc), I'm currently making my own mod which does not edit existing files and only adds offline combat.
Planned features ATM are actual combat (taking into account equipped weapon accuracy, recoil and DPS, and using NPCs' real immunities, and for mutants attack damage, speed etc... I'll explain in detail once it's released, the mutants are a bit tricky), notifications about combat via the existing dynamic news system, spawning of online-object corpses when player approaches spots where NPCs died in offline combat, distant noises of offline combat in the same level. The latter things will be added in updates after the first release, but I already finished the code for the first featured I listed, though I didn't put to it use yet.
Separately I will make addons that enable looting of corpses killed in offline combat, offline stashing of said loot when approaching carry weight limit, trading of said loot when idling with friendly/neutral squads, selling of said loot when idling near a trader, returning to created stashes to sell that loot, map icons of friendly squads and faction squads + enemy squads visible to the previous ones, and variations of the original mod with gradually less accurate simulations (in case the base mod is too performance heavy)... I think I had more ideas but I don't have my notes nearby
Optimisation is important to me since quite a lot of calculations are made for a script (as opposed to a program in native binary - fortunately Lua is relatively fast for an interpreted language, and LuaJIT ridiculously so), but I'm familiar with Lua's semantics and Alundaio has given me some implementation tips as well
But because of this, and because I have trouble in general finding time to work on it, progress is slow