That's one thing. The other thing is that "a forwardness in the upper midrange and lower treble" is a universal assessment nor is it supported by measurements of the amp. Personal preference may be the issue and that cannot be discounted nor should it.
The problem is in the term "better." There are many other excellent amplifiers and I will not deny those who choose other than the Benchmark. What, specifically, do you need to fix or improve or, alternatively, how does the current amp fall short?
Why is that hard to believe?
Soundstage? Unlikely to better than a single stereo amp.
Separation? Only if the separation of the single amp channels is inadequate.
Better performance? Too nebulous to say.
I've added a second and a third but my reasons were based on the ergonomics. There...