No drop cover by user and loop cover by mixnode in Nym?

[youngjoon-lee]

Hi, I'm taking a look at details of Nym implementation with comparing it with Loopix.

From my understading after reading this Nym implementation, it seems that it produces loop cover by user (mix client), but doesn't produce drop cover by user and loop cover by mixnode (which are described in Loopix).

I've read that Nym has some modifications on Loopix. I'd like to ask if this is the modification if I understand it correctly.

If so, I'd like to ask the background of this modification.

What I guess is:
With regard to the drop cover by user, I think it's because drop cover is basically the same as loop cover + it also helps the receiver unobservability.
With regard to the loop cover by mixnode, I guess it doesn't has the concrete effect on privacy, compared to loop cover by user. Loopix says that loop cover by mixnode keeps the mix network online even if there is no real traffic. But, I think loop cover by user also does this.
Additionaly, Loopix says that loop cover by mixnode helps detecting n-1 attacks, but I'm curious how Nym does this without loop cover by mixnode.

Thank you for providing this nice design and implementation with the community.