Open circuit tech divers: I don't know what the kids are doing these days, but in my day, tech diving was all about planning and situational awareness. So while you still would check tank pressure on occasion, a tech diver has a MUCH better awareness of his or her typical consumption rate, and less overall anxiety about the dive. So they are probably only checking their tank pressure occasionally (maybe every 5-10 minutes). There is always a tradeoff in these choices, and by putting a tank pressure reading on your dive computer display, you are displacing some other piece of data - either by making the numbers smaller to fit more into a limited space, or shifting it to a secondary screen. Since you don't need to constantly monitor tank pressure, why not just have it on a plain old SPG that you can glance at occasionally?. That single HP hose coming down your left side and clipping to your left hip is about as unobtrusive as scuba gear can get.