Three Easy Questions for a SD Bake

Toast

Baking a "multigrain" "Vermont Sourdough Rye".  Three easy questions:

1.  Would like to add some extra flavor by adding a powder mix of anise, fennel, coriander, caraway.  OK to add this directly to the bread-flour/rye-flour mix just before adding water and levain, to begin the autolyse .

2.  Recipe calls for 3 "stretch and fold" actions during fermentation.  Heard that "letter-folds" (flatten dough and then tri-fold like a letter) might be better .  Make any difference?

3.  Would like to add the usual mix of toasted seeds (sesame, sunflower, pepitas, caraway, quinoa) and grains (rye berry).  When best to add these to dough?  End of autolyse?

1.+3. I don't think adding spices and grains to the autolyse dough will affect it in a major way. Though I could imagine that grains interfere with gluten development if there are too many of them. Just to be sure, I would add spices and grains quite in the end of mixing the final dough, when all other ingredients are combined.

2. Every baker has a different technique. I believe it doesn't matter that much how you do it, the most important is that you don't deflate the gases. Especially towards the end of BF, the dough will be gassy, jiggly and have tension, so handle it gently then.