If you feel smooth release and hair in anagen come up with bulb and sheath than you make a great work.
The 2 hand progressive method is the recommended for blend but I forgot that you are DIY ,so you are right, using it will be extremely difficult in that area.
You can continue working using your best method to make the best possible insertions.You can play with the time-fine hair less time, thicker hair more time ones you establish the DC current. Also you can use the "treat and wait" method. Treat one group of few hairs than treat second group of few hairs,than remove the first group of hairs and so on. The Lye in the follicle will have more time to work. If some of the hairs do not release smoothly you can remove the hair than insert the probe in the empty follicle and make after-count for a few second.
The frothing lye coming from the follicle is perfect but this is not always the case and, if you wait to see it, you can over-treat the follicle or the insertion is not exact.
If the probe is non-insulated you do not need to move it up and down but the best is to use tapered, one piece probe.
In both case you have to be extremely careful not to damage the upper part of the skin.(because you do not use 2 hand you can not test the hair)