Based on memory, you're already loading all samples/attacks/loops/releases at 24 bit compressed, which is good.
It would help to know where you believe Hereford needs to improve in sound quality on your system, if you have examples of what seems to be subpar. Also, a description of your audio components is highly relevant.
So, some generalities:
1. Windows tuning for audio is covered in the Hauptwerk user and installation guide. See the Performance tuning section. The i7-8700 is more than sufficient for Hereford XL if tuned properly.
2. Audio driver help would require knowing your audio interface make and model, but it's usually limited to the sample rate and buffer size parameters discussed in the HW user guide.
3. Tuning for audio within HW V is also in the HW user guide, in the section mentioned above and the chapters on audio mixing. Polyphony setting for your CPU, rank voicing, rank routing, mixer groups and buses all factor into audio quality, mostly in the sense of making it worse if you haven't thought through those settings carefully after understanding the documentation.
4. Fidelity was greatly improved from V to VI by two new options: Higher definition pitch shifting, which affects a lot more than just temperament changes and base pitch adjustments. 96kHz sample rate, if your audio interface supports it, makes an even bigger difference. Moving to VI is the single biggest improvement you can make.