Exactly what I also feel with low gains. High gain seems too brighten(not clear) up but low gain makes it feel like more headroom, and more controlled at same levels of comfort.I had mine setup XLRed to A90 amp.
Recently, I had to shift stuff around and ended up taking the A90 amp off the chain (which meant switching to single ended cables for the HPs)
I have always had issues with high gains on most devices and prefer low gain (for me the sound becomes less spacious with less separation in high gain mode)
The Heddphone requires some oomph to drive it but I found the SE out more than adequate for them… so no longer have an external amp in the chain now… anx run all headphones in low gain through the TT2.
The soundstage sounds “tall” with high gain. With low its more wide. May be placebo, but I keep it on the low