I'm nearly always posting with a laugh in my step and posts. No frustration or anger here.
Yes, of course you have current polarity reversals on ALL 6 of the settings. Any time you feel a shock (thats if you dialed in a high enough setting to feel it) that IS a current reversal. So on the 4 hz setting, you are feeling/experiencing 4 shocks per second for the four cycles per second which equals 4 hz. 4 hz equals 4 cycles per second equals 4 polarity reversals equals four tiny shocks. You do not need to feel the shocks cuz .5 millamps is enough! Some people would say that there are actually 8 reversals I think for 4 hz. Not my area of expertise.
There really is technically only one setting that beck was using himself in his design. 3.92 hz (hertz) so that is close to the 4hz setting. All others are newer mods others have come to desire in the last few years. 4 hz still provides great results of course.