Enhancing already existing audio is not cheating. Similarly, using better headphones or a bigger monitor is also not cheating. HRTF in games will give you better information than these programs can. They cannot magically make new information. On the other hand, HRTF in games that support it uses math so that you can hear things above and below you and more accurately place steps.
HRTF will do a lot more for you than an equalizer or compressor could.