Yes, stacking basic materials like ore, logs and skin would help, and yes it's not fair that you can HQ lumbers and not leathers or ingots, sheets.
It's also strange when you make bolts, it's better to try to HQ them separately than using Boltmaker's Bundling Twine.

It would also be great if we could set the number of synthesis we want. (even x12 would be great)
For example, as a corsair, when i want to make 12 pouches of bullet it takes me awhile, i could have use this time to make things at home, or watch TV, surfing the web, while my character repeats the same synth over and over.
I know there are third party programs that can perform this, but i would prefer a legit way to make crafting less tedious.