The heart of "SupremeFX" is an ASUS-programmed Realtek ALC1150 10-Channel HD Audio Codec. The ALC1150 admittedly has a bit of tainted rep with gamers and audiophiles - because it's never going to outperform a proper dedicated sound card - but it has truly excellent specs, it's fairly robust, it's cheap (in bulk, anyhow), it's well supported (if you're an OEM, anyhow), it's highly customizable and it's surprisingly versatile. ALC1150 chips are used in USB gizmos, low-cost PC audio cards, high-cost PC motherboards, "professional" instruments and audio consoles, and a wide variety of consumer appliances. Hardware specs include:

• Intel HD Audio support (PCM up to 32k/44.1k/48k/88.2k/96k/192kHz sampling rates and 16-/20-/24-bit resolutions), legacy analog support, legacy (Realtek) codec support
  
• 10 output DACs (primary 8-channel 7.1 Surround playback at 115dB/96dB SNR, secondary 2-channel independent Stereo "multiple streaming" playback at 110dB/93dB SNR)
  
• 2 input ADCs (Stereo mic at 104dB SNR with software-controlled Acoustic Echo Cancellation, Beam Forming, Noise Suppression)
  
• 8 retaskable analog I/O jacks (with three jack sense/detection pins, three analog output amplifiers, four analog input amplifiers, "anti-pop" mode output support)
  
• Full Rate Lossless Content Protection DRM firmware (for I2S, streaming, software media, CD, DVD, HD-DVD, and Blu-Ray playback)
  
• Windows-optimized (Vista/7/8/10) software-controlled power status monitor and controls (with 0.75dB volume stepping, +10dB/+20dB/+30dB gain boost, Dolby TrueHD and LPCM emulation)
  
• 48-pin QFN "Green" package with 1.5V/2.3V/3.0V/3.3V/3.8V/5.0V electrical interfaces, full Intel Low-Power ECR compliance, integrated whole-package LDO, HD Audio Link, DTS, optical/SPDIF, I2S bus, 2 GPIO pins
  

"ROG Audio" (the precursor to "SupremeFX Audio") was basically just an ASUS-programmed ALC1150. The ASUS implementation was largely uninspired (copied straight off the ALC1150 datasheets), many ROG "innovations" (like PCB audio trace shielding, PCB layer isolation between channels, package EMI/RFI cage, "audio-grade" Nichicon filter capacitors, etc) strictly adhered Realtek's general and specific recommendations/suggestions for using this part. Other ROG "innovations" (like Sonic SenseAmp, Sonic Studio, Sonic Radar, etc) were primarily software-based tools which emphasized ALC1150 hardware capabilities. ASUS apparently linked the ALC1150 to/through the ROG Chip (on at least some boards), and apparently for no reason other to prevent non-ASUS software from successfully reflashing the ALC1150 firmware. I haven't personally confirmed this.

"SupremeFX" is more than "ROG Audio", ASUS added some more discrete hardware parts to extend ALC1150 capabilities. Most notably a 2Vrms stereo headphone amplifier circuit (an ESS 9023P "Sabre" 24-bit stereo DAC driving a pair of TI RC4580 audio op-amps), an NEC UD2-4 5NU signal relay to strengthen "de-pop" (although the ALC1150 itself supports a limited "anti-pop" mode), and a dedicated clock. This all adds up to a cleaner, crisper, richer, and more "natural" (or, alternately, less "artificial") audio output - on the dedicated 2-channel (stereo) front-panel headphone audio output, anyhow.

Note that "ASUS-programmed" means ASUS designed the firmware and parameter presets/boundaries encoded into their ALC1150s. Realtek provides tools to their OEM customers - ASUS, Gigabyte, MSI, etc. My experience with "ASUS-programmed" ALC1150s is that ASUS primarily emphasizes built-in features and functionality and compatibility, while emphasis on raw performance or quality is secondary (and you just can't have it all when there's tradeoffs).

An answer to your question:

The ALC1150 audio chip supports jack restasking (with certain limits, although it could easily do exactly what you want) - but it would need different software and/or it would need different firmware - and if your ASUS-provided stuff doesn't do it (yet) then I doubt it ever will. Also note that the rear-panel jacks wouldn't benefit from circuitry hardwired into the front-panel jacks.