I would like to get any advice of dilution of this developer in order to use and throw, per 1 liter.
I used this developer many years ago. It is very good and it is designed for re-use. It is very highly concentrated. It will be nice for me now to find a sort of compromise between extending time (more dilution) and throw, knowing what I will be throwing could be re-used. l think a dilution putting me on 12 minutes will be fair enough.
I think you are right with the 1+47=48 litres since this means a total of 48 litres x 3 rolls each = 144 rolls.
I guess that re-using, this developer may give more that 1000 rolls. However, being realistic about the amount of rolls I will make during a year, 144 is more than fair enough.