It would have taken twice as long had I used the step method. I would like to see any data that indicates the amount of cell degradation difference using the step method and setting the PS to 3.65 volts.Yes, it takes a bit more time, but 3.4V means less risk during the long part of the top balance and will not degrade your cells as bad as trying to achieve 3.65V in one step, if you're not there to watch it.
I have a fairly good understanding regarding voltage drop. My Riden hums along nicely putting out the full 12 amps. I used it to parallel top balance my cells, to charge my cells several times after connected in series, and to charge my Valence batteries with the PS running at it's full output. Many others have used the traditional PS's running at their full output without burning them up. But setting those at 80% output is good advice.The voltage drop between the PS and cells has not changed and by increasing the CV, and thus putting the PS back into CC / bulk mode, the 12A will create even more voltage drop. Also keep in mind that you don't want to run these small supplies at more than about 80% for continuous use.
I didn't want to spend a lot of money on a power supply for a one time use. I opted for the Riden due to it's many features including the charging feature. Granted it wasn't that cheap and I have no regrets buying it. As you said using a voltage sensing PS would be the safest way to parallel top balance. I trusted the charging feature of my Riden and slept while my cells were charging although I was awake to watch my cells reach their end of charge. I had tested the Riden on my Valence batteries before I parallel top balanced.Higher quality power supplies utilize a dedicated voltage sensing circuit, but these are significantly more expensive. We have a few small PS in our shop. One is a 5A linear (no v-sensing) and we use 6AWG wire on it to have an extremely low drop between the PS and cells. Most of our larger models, 60A etc., have built in voltage sensing making this sort of thing a non-issue..
I know another member used 6AWG wire with his Riden and had the same issue I was having. His didn't put out the full amps until he adjusted his PS above 3.50 volts. Personally I used 12AWG cable.
I am not arguing against the step method and to each their own. My Riden went into CV mode when the cells reached 3.391 volts and it took another four hours to finish the charge. So the cells were not held at a high voltage for very long and if there was any degradation I doubt it could be measured even if it could be measured.