"When I read in an official technique book, or Richard Hearn in his letter service states in writting, that the third steps of a Feather is 1.5 to 1.75 of a beat then I will beleive it."
You will not read it in the technique book because FOXTROT IS NOT ABOUT FOOT TIMING.
IF foxtrot were a rhythm dance - if it were about foot timing - then the way foxtrot was documented would be a lot more like the way cha cha cha is documented. There, each figure is offset from the bar - it starts late on beat two, and it carries over to the beat one of the following bar.
The classic SQQ action of foxtrot in fact has the same sort of carryover. But not exactly by a beat - instead, it's by a messy, subjective fraction. The fact that it would be messy to document it accurately is the minor reason why nobody has updated the book to accuretly reflect this.
But the major reason no one has seen fit to "correct" the book here is that OBSESSING ABOUT FOOT TIMING WILL NOT HELP YOUR FOXTROT. Foxtrot is a dance that is about the body movement - you SHOULD NOT BE THINKING ABOUT YOUR FEET.
The only reason you need specific information about foot timing is to correct wrong information that you've somehow picked up. You would be a better, more fluid and natural dancer if you had never asked the question of foot timing in the first place. But since you've chosen to ask the question and interest yourself in the subject, you will need ACCURATE INFORMATION TO CORRECT YOUR MISTAKEN IDEAS.