The latest talk at FTA is about resistant starch, and using raw potato starch as a supplement for getting resistant starch, which helps control blood glucose.
The potato diet/hack is about weight loss, it's as described in this thread--eat potatoes, lose weight.
Sorry you got the two ideas confused.
However, your BG response to a huge potato-only meal wasn't so bad, about the same as mine. A really bad result would be well over 200 for over an hour. Are you on any meds for T2D?
If you want to try the RS approach to BG control, you would mix 1-4TBS of raw potato starch in some sour cream, and put that on a potato and check post-prandial BG--I think you would see way less than with potato alone.
I think in this thread, it was discussed that the potato hack/diet for weightloss is not advisable for someone with BG control issues, although with the pp's that you reported, I would say you could do the potato diet for a few days and you'd probably see those pp numbers come down and FBG be stable. However, if you are on meds, I don't know...
A normal, slightly insulin resistant person would see a spike between 150-200 about an hour after consuming a large potato meal, it should be almost back to normal at 2 hours and for sure at 3. Some hypoglycemia is normal for a very short time between 2-3 hours because of the huge glucose load and insulin response.