I have been using my3206 scope for a couple of years. When I used to go below 200mS/div, the scope would drop into roll mode, or what you call continuous sampling mode. Any which way, the trace was continuously updated.
I have updated the software to Picoscope 6, and I find that it no longer does this, in fact slow sampling times are practicly unusable! When I tried fumbling about in the options, it says continuous sampling is not available on this oscilloscope. It used to work, what am I doing wrong!