Sante Fe Bill,
Now that I have seen your baguette recipe, I have a better feel for your question.
Technically, your recipe does not use an autolyse in the classical sense. As originally conceived, an autolyse entails mixing just flour and water and letting the mix rest (autolyse) for 20-30 minutes so that the flour can absorb the flour without interference from anything else. No yeast is generally added to the mix to begin with because adding the yeast would start the fermentation process and the dough would begin to acidify. This would be especially true with compressed yeast because it starts to work faster than dry yeast. It would also apply to a preferment, especially one that has been fed and is ripe, such as yours. Sometimes IDY is allowed in the initial mix for short autolyse periods (under 30 minutes) because it is slower acting than compressed yeast. No salt is added to the initial mix because it tightens the gluten and hinders its development and its ability to absorb water. Your baguette recipe doesn't call for oil, as do many pizza dough recipes, but the oil would also impair the flour's ability to absorb water (oil is hydrophobic, that is, it repels water).
As you know, salt is often used at the very beginning of making a bread dough (it is usually dissolved in water before mixing in the flour and other ingredients). One of the reasons this is done because it reduces the oxidation of the dough so that the components of the dough that contribute to the color and aroma of the finished crust (complex carotenoids) are not harmed through oxidation. However, if you use a true autolyse and add the salt later, the same effect should take place because one of the principal benefits of using an autolyse is to reduce the overall knead time. The process of kneading itself oxidizes the dough, so foreshortening the overall knead time will mean less oxidation.
Rest periods other that autolyse rest periods generally have the effect of allowing the gluten in the dough to relax. Kneading a dough is rough on the gluten, so when the dough is allowed to rest after being beat up, the gluten relaxes. The gluten will always relax during a rest period. So, as between using a rest period at the beginning as opposed to the end, as raised by your question, I think the answer lies in what is in the dough at the time of the rest period. In your case with your baguette recipe, you mix everything together at the beginning. So, you technically shouldn't get most of the benefits of a true autolyse. Short or long rest periods after that will help the gluten relax and maybe you will get modest hydration but you won't optimize the process.
Since autolyse is commonly used in making baguette dough, I think it would be interesting to alter your mix/knead regimen to use a classical autolyse to see if you like the results you get. I know from your other posts that you favor high hydration doughs, so you might be able to coax out an even higher hydration by increasing the amount of water (relative to the weight of flour) at the very beginning-- before the start of the autolyse rest period. Theoretically, that should lead to even bigger holes in the crumb.