Well, there is a middle ground: when you haven't written that big framework/engine, but could have, delving into the source code in an as-needed basis may sound like a decent option.
Of course, you're hoping your framework is fit enough for your purpose, so that you rarely have to inspect it —if at all.
Of course, you're hoping your framework is fit enough for your purpose, so that you rarely have to inspect it —if at all.