@awang
Yes, this mod has a flat gain across all frequencies. Audio Muffler Redux has some neat features — it may be possible to combine the mods (i.e. as one mod). Alternatively, Sonic Realism could have a flag of whether to mute sound by atmospheric density, which shouldn't be difficult (but may be difficult nonetheless in C#, cuz it's C#).
The latter is likely easier but the former seems preferable. This is now on my agenda — no guaranty it will happen soon, but will try to make time. Meanwhile, if you care to build the mod yourself, you can use the branch "no-mute-by-density" from my GitHub repo, which has only the shock effect.