You're a beginning diver, and shouldn't be "re-inventing the wheel" yet. Keep your equipment simple, and give yourself more "bottom time" with the equipment configured like in your basic open water dives.
When you're past 100 dives, judge the equipment other divers are using and adopt your own choices. Some of those choices may be bad, but with experience, you can make a bad choice, without endangering your self.
Spare air, is an option for an experienced diver. . . adding more toys to keep under control, while you're still learning the basics, is making your starting dives too complicated. What length hose, and routing the hose, is something you need more time with the basic configuration.