I did not test it with Mojo 2. I would say that it might drive it from a volume perspective, but from a dynamics perspective and precision, it should scale with more powerful amplifiers.
It does scale, a lot! Volume-wise, the hekse will play fine even from a phone or a laptop, but dynamics and bass just keep getting better and better with better driving. I started using it at times from my phone and laptop, at times with a THX AAA 789 fed by a Violectric V800 with Xmos, then I heard it from Hifiman's EF400 and EF600, then I started using a Schiit Bifrost 2/64 + Jotunheim 2, and now I upgraded to the Mjolnir 3, still fed by the Bifrost. At each step in the list the Hekse sounded better and better, moving from the THX to the Schiit rig was a big jump, BIG! Obviously these headphones don't perform too well from Class D, and the story changes dramatically moving to Class AB and particularly pure Class A. They suddenly had macro-dynamics I had never heard before, an increase in quantity and quality of the bass, the hot treble became more controlled and sweeter, and sound was presented in a much more spatial way, more 3-dimensional, ultra accurate imaging/separation, in a very vast stage. And finally, moving to the Mjolnir, yeah... it is now amazing, crazy good! Incredibly resolving, very dynamic, with very material punch and bass slam, the timber of anything is ultra detailed and spooky realistic, almost Susvara-like spooky. And if anything bothered me about the headphones tuning (they are a bit bright), with the Mjolnir I am really not bothered by anything, pure pleasure.
