You are calling lines overweight because the total weight of the head is more than the AFTMA standard. That shows your lack of knowledge, Rob. AFTMA is a weight for the first 30 feet of line, regardless of head length or taper. The only exception to this is Spey, which is a lot more complicated. You’ll notice that even Spey lines have different AFTMA weights depending on the type of line or head (https://www.affta.org/wp-content/uploads/2012/01/spey_line_weights.pdf).
Here’s the standard weight chart for reference https://www.affta.org/wp-content/uploads/2012/01/fly_line_weight_specs.pdf
Again you didn't listen to a word i said.
What i am calling abuse as if it wasn't clear by my sex dungeon example. Is people abusing their rods by using heavier lines for the purpose of using flies that are too big for the rod. It doesn't matter that the rod will do it it matters if the rod is built to do that and the end user is clueless as to how the rod is constucted.
Here is another example, an extreme one.
Competition spey rods manufacturer builds a rod for a 1000 grain line. The caster can cast further if he bumps the line to 1200 grains and it casts really far and really good but he starts breaking sections.
Wanna frame a house with ball pern hammer? No of course not. Anyone attempting to frame a house with such a hammer is gonna break something.
If you want to fish a 5 inch bulky streamer with lead eyes a long distance an 8 or 9 weight is the proper tool not a 5 wt and a rio outbound.