The theory is almost correct, and that is that as you give a 100% vote your power will go down.

At least that's how it happens to me, a practical example.
No 100% vote is close to 1.67 POB,
My first vote at 100% receives that amount, my 2nd vote at 100% decreases and will be approximately 1.62 POB and so on, before my voting power is around 80% my 100% vote only allows me to give a cure close to 1.45 POB.

On average I can do that about 6 or 7 times before I reach the limit of 80% of voting power, this allows me to come back the next day and see my voting power recharged to 100%!