Incursion: a possible solution for the Augmented Capes

[Crevox]

Yes.
But as I stated before, Megaboss NQ crates have roughly the same chance of content being a cape as normal bosses' HQ crates.
When you factor that in, most likely you'll get more chances to get what you want from Grammk's coffers, despite the larger pool, compared to farming specific bosses for a specific type of cape.

Even if this is accurate, it goes from being a 1/5 to get the cape you want to being a 1/22.

Is that really worth it?

You might say like, oh, well you can get any of the other capes too, so you might get one for another job you want, but I literally only care about the SMN cape. The GEO cape might be nice (even though I have one already), but I don't care enough to bother. I only want the SMN cape.

[Zhronne]

Even if this is accurate, it goes from being a 1/5 to get the cape you want to being a 1/22.

I'm no math expert, but I think it's different than that.
Allow me to make a silly example using fake numbers. Let's say this is the (fake) table with rates. It shows the chance a coffer will have a cape (of any suitable type) inside.

NQ Boss => 5%
HQ Boss => 10%
NQ Mega => 10%
HQ Mega => 15%

Now you have to consider how many crates each killed NM drop. Let's say ilevel 129, I don't remember how many crates 129 drop, let's say 7 since it's just an example I'm making.
These 7 will be split between NQ and HQ, depending on luck and TH. I dunno about average but let's say uhm 5 NQ and 2 HQ?
So a more accurate comparison would be:

5x 5% + 2x 10% ==> * 1/5 (chance of being a cape you want)
versus
5x 10% + 2x 15% ==> * 1/22 (chance of being a cape you want)

Another important aspect you might consider outside of these numbers, is that if you're fighting MB you won't have to bother to find people specifically interested in that specific NM and who also have the jobs you need.
Anybody will be interested in MB.



tl;dr
Not saying it's completely worthless to target a specific boss, especially if you have the good conditions/friends to spam it.
But do not rule out MB runs like I used to do.
I used to think like you but had to change my mind after reading reports from Malithar and other people on BG forums.
Now I kinda prefer to spam MB runs honestly. It's just faster, more efficient, and in the end I manage to make more runs (i.e. even more chances) thanks to the time I save setting the group up.