There are only two times where synergy really matters:
1. the source, DAC, or amp uses valves, and has high levels of distortion. (This goes for certain NOS DACs as well.)
2. you're not looking for the best possible sound, but for a certain sound.
If it's the first, it won't matter: Mojo is solid state. If the second, Mojo won't matter as it is 100% capable with every IEM on the planet, and in many metrics, is the best or 2nd best performing DAC/amp out there. So, for it to have or not have synergy with an earphone would mean that the product you're looking for has worse objective sound quality. In which case, I can suggest about a hundred DACs/amps with more or better synergy. Synergy with earphones depends on only three things: personal preferences (which have nothing at all to do with objective sound quality), sufficiently low enough output impedance, high current. It can fail the last two and still have synergy for you, but that synergy is predicated on BAD sound quality.
Mojo plays perfectly well with TG334 and MH334. But it plays perfectly well with all earphones. Again, if you want worse SQ, just ask. The options are myriad.