>> But as far as what I know hot descendants of sweet peppers will appear only in the following generation, not those simply pollinated by a hot pepper pollen.
That's my understanding also.
>> Once the tube reaches a given ovule then they merge and fecundation has occured and the formation of the seed embryo starts. Only one pollen grain of the many that try to reach each fertile ovule.
There are many seeds per fruit (or berry - the whole pepper that we pluck from the plant and then eat).
But it sounds like there are only (3 or 6?) ovules per capsicum berry or fruit.
Then I assume that each ovule can accept many grains of pollen, and produce many seeds ... but only one seed per grain of pollen.
Am I still following you?
