should always be 16 and 48 Khz . nothing else. for Mastering you use 2 Speakers should be 24bit 96 Khz or even 192 Khz

The issues you will have is Virtual Surround not working, some weird issues with sound , some random artifacting and sometimes crashes because of it . some application won't even work properly or at all.

Most "audiophile-grade" sound devices are rated for 24-bit/192KHz. Not a technical standard, just a de-facto one which has become popular through common usage.

The general consensus is that higher bit-depth and sampling specs are basically meaningless because they're imperceptible to the human ear, although some audiophiles argue (rather vehemently) that richer and faster digitization provides finer resolution so it must logically always be better. (And, of course, some audiophile purists still continue to argue that nothing digital is *ever* actually audiophile quality, lol.)

From an engineering standpoint, unnecessary rescaling and transcoding will never (by itself) improve playback fidelity/quality of recorded audio but it can introduce digital artifacts and electrical noise which actually diminishes fidelity/quality.

From a practical standpoint, I'd use 24-bit/192KHz as a baseline, then experiment with other settings, then retain the ones which actually produce whatever sounds best.

And there's no need to upscale audio quality beyond the resolution of the recorded sound source. Most digital audio files in games, movies, and music (even the uncompressed or "lossless" ones) were encoded at 16-bit/48KHz or up to 24-bit/192KHz, playback at 32-bit/288KHz simply can't and won't improve the way they sound.

Your Beyerdynamic DT770 headphones are 35 Ohm, best to use that.

Higher impedance on the headphones means they require more electrical power (audio signal) to drive the speakers at the same amplitude (volume). If you set the audio hardware for higher impedance then it will push out more Watts.

Too little drive will produce low-amplitude flattened waveforms - the headphones will sound very quiet and lose a some audio depth/quality on playback.
Too much drive will overdrive the audio output transducers - the headphones will suffer damage which de-rates their specs and even overheats them, the damage might be temporary or permanent, it might reduce sound quality immediately or gradually over time.

There's no hard limits on analog tech, selecting the "optimal" balance is a bit of an art/preference and has wide tolerance. No reason to exceed the 35 Ohms rated by your manufacturer, if you need louder peak volume then you (well, your headphones) would generally be better off using an in-line audio amplifier than overdriving the source.

10% seems like a lot of resources for audio, lol. I suspect the original audio sources (game sound files) are encoded at lower quality and software is upscaling them to playback at higher bit depths and sampling rates.

You have an ASUS STRIX DLX soundcard and i5-6600K CPU. But which motherboard, how much RAM, which WinOS and audio driver versions, which version(s) of Battlefield?

I don't play any of the Battlefield games, but I see that there's many sound mods for them (including some which claim to "fix" poor audio quality).