Piggy backing on this. Thinking longer term, would this be a good base for a sidemount setup?
You could do that if you wanted (and plenty of people do). However, in my experience it's convenient to have a dedicated single-tank reg set and a separate doubles set:
- I sprained my ankle this summer and wasn't able to walk with BM doubles. No problem, I dove single-tank and I didn't have to swap any hoses to do it.
- On long quarry dives, my singles reg set goes on my stage bottle and I just tuck the extra hoses under the bands.
- If you blow a hose or have some other failure on your doubles set or just need an extra (e.g., drysuit hose), you can scavenge off of your singles set back at the car.
- Let's be real! If you get into tech diving, you'll start finding all sorts of needs, wants, and excuses to get extra regs for what you want to do. The more, the merrier.