Mark,
Hope life is going well down in Norcal and the diving is still the "get in shape hike" that it is. I'll second that buddy thing you mentioned. After a few dozen times inflating an SMB, it really comes as second nature. I figure I'd addd in my comment early on a Sat morning...
You can do it well under a minute. Slow is smooth and smooth is fast. There's no real need to take a deep breath, just breathe normally, pull out the smb and rig it to the spool or in most cases, it's already pre-rigged. Taking a deep breathe forces you to go negative with the BC. Better to just practice staying neutral. Since you're in green water, without bottom reference, your buddy maintains depth. He/she should also give you plenty of light while performing the task. The buddy should also signal you if you are losing bouyancy more than 1-2 ft. Light is best clipped off while both hands are undoing the bungee wrapper. After both hands are done undoing the SMB and cliping off the double ender to the D-ring we generally keep everything on the right hand. Middle finger and thumb around the spool and index finger around the inflator. Exhale once to get the SMB neutral and another exhale to give it enough to lift off. Gas will expand, so no need to inflate all the way. Left hand is free to manage bouyancy (drysuit dump valve, BC inflator, drysuit inflator) provided you are rigged DIR and have the left side only for bouyancy management. Right hand is always out in front with the spool and depth guage/timer. Again, provide you are rigged DIR and have gauges on the right hand. The spool will get passed back to the left hand temporarily while the double-ender is being clipped in by the right hand. Done deal, all in 30-45 seconds. While all this is going on the diver is constantly doing the triad: checking depth, line, buddy/surroundings, all the way from SMB deployment, thru deco, up to the surface. Of course your buddy chillin ought to pick up the deco responsiblity. Typically, bag man and deco man are not the same individual.
Hope that clutters the mess some more.
Sincerely,
H2