I hope not. While the classic 3-speed Sturmey-Archer AW seems to have acquired the (deserved) reputation of God's Gift to Internally Geared Hubs, S-A's other attempts never really lived up to it.
One of my two commuters is a '69 Raleigh Sprite, which is essentially a Raleigh Sports with the S-A S5 5-speed hub in place of the AW. It works, but it's not a nice easy job of shifting 1-2-3-4-5-4-3-2-1. To begin with, functionally it's an AW (right lever) with a overdrive/underdrive (left lever). Putting it in low gear on the right (narrow range low) then pulling back on the left lever gives you wide range low. Aka, extra low. Likewise, if you're in high on the right lever (narrow range high) and pull back on the left, you're now in wide range high. Extra high, overdrive.
Except that the left lever never seems to shift nearly as crisply as the right lever, and sometime will bloody well refuse to connect unless you flat out stop the bike. Because of this, I tend to use the bike as a dual 3-speed, running 2-3-4 on the right with the left lever forward, and 1-3-5 with the left lever back. Other than that foible, the hub is quite reliable and works quite well. As I've got the bike geared perfectly for me on the flats when in directly drive (3rd gear), I will usually set up the left lever in advance for the terrain I know I'm going to be riding. I have three shopping centers within a 4.5 mile radius of my house, two of which are pretty much on the flat, the third having on hell of a climb coming home. So it's easy enough to setup for the 1-3-5 combination just before I hit the drop/climb. I've gotten reports that adding a spring between the left side cable and bell crank takes care of the problem, but have yet to mess with it.
Did I mention that the levers were absolute crap with poor indents, snapped easily, and are absolute unobtanium? To the point that I've got filed to do 3-D printing of an equivalent if I ever decide to learn how to mess with a 3-D printer. For my bike, I've got a regular AW handlebar shifter for the right side, and am cautiously using the original left side lever. The levers more than the hub itself were the source of it's slightly dodgy reputation.
I don't see how you could take a classic S-A and turn it into a 6-speed. Possibly something could be kludged using the above system on their 4-speed hub (can't remember the model name right now, sorry), but given that since that hub had a much less than stellar reputation for reliability and longevity, I don't think it'd be worth the time.