There is one. I's called Executor.
Executor, being derived from Pegasus, is midline, and it has midline engine flames.
Also, Heron with its energy mounts and its relatively smooth appearance would be fine as a high-tech ship, but it has midline colors. All Heron needs to be a high-tech ship is a color-swap. Most other midline ships are either too blocky or angular and/or have ballistic mounts for a mere high-tech color swap conversion alone to work.
Would be nice to have a symmetrical conventional high-tech cruiser (no phase ships, no automated ships like Apex). Apogee, Fury, and Aurora are all unsightly asymmetrics.
If the game did not classify phase ships as high-tech (low-tech in case of Gremlin), I would not even think of them as high-tech, just phase tech, as separate tech of their own. Phase ships look more like mod faction ships than a normal high-tech ship. Probably could give them magenta engine colors to make them stand out more. I would say purple engines, but Omega ships claim that color.
All phase needs to be a faction of its own is another combat-capable phase destroyer and cruiser, and maybe a battlecruiser (on par with Retribution or Nova) if Ziggurat does not count or is too bleeding edge or overpowered. Phase has Afflictor and Shade (and Gremlin, but the style is different) for frigates, Harbinger for destroyer, Doom for cruiser, and Ziggurat (if we count it) as a battleship-tier capital.
Re: Nick's two-fisted Apogee.Looks better than the original. Symmetry is good. Although it would be overpowered if the hardpoints were all larges.