Yeah, I will ask dudes at GearSlutz forum.
The thing is, they don't know as much about headphones as you guys do.
But, definitely the majority of Audio Technica, Hifiman headphones are for entertainment rather than pro audio reference.
Especially, Hifiman seems to have no intention for that purpose at all.
Sony makes respectable studio headphones but I doubt the MDR-7520 is going to give you anything the SRH1540 doesnt already. Maybe try Focal or KRK headphones seeing as both of those brands also specialize in studio monitors.