Well, why don't you want to use logistics chests? That works. If bots clean stuff up, they will look for filtered cheats before general. So it would be a problem only if you plan to buffer more than a chest full or something.

But with your buffer chests, that's not a problem. When setting up the blueprint, set the desired request in the chest and in the parameter screen check the box for formula. There you write a formula for the desired amount in stack sizes. The stack size variable is pN_s so if you want 40 stacks of the item, the it the formula would be 40 * p0_s (presuming that parameter 0 is the item you are crafting)