There is not a mandatory mixin feature. Tx fee is not variable.
Your own presentation, page 9 and after talks about nothing but forced mixins:
http://www.slideshare.net/boolberry/boolberry-solves-cryptonoteflaws-37055246Also, your developer has said you are wrong here also:
It
does, because it:
...FORCES other people to use some specific level of mixin factor in future transactions....
And this is precisely showed in our presentation.
Also, this is discussed here:
https://forum.cryptonote.org/viewtopic.php?f=12&t=239Additionally .. are you joking or serious that the tx fee is not variable with the size of the transaction? Not much of an abuse deterrence here, now that you're entirely dependent on forced mixins to provide 'guaranteed' anonymity.