I do not see the need for bitUSD_2
I don't pretend to understand everything here properly. But it seems that if there was a successful attack on BitUSD1 that drained the reserve fund and created a large amount of unbacked currency that BitUSD1 may go quite far away from a peg that resembles the value of a USD.
If you identified and corrected the cause of the attack you could start BitUSD2, which would start from scratch and be fully backed and therefore trade closer to a USD peg.
-It should be highly unlikely to have not fully backed bitUSD;
-The unbaked/not fully backed bitUSD is not the end of the world;
-The proposed system provides a way to 'eat them up'/remove them over time.
On a different issue:
'fully backed and therefore trade closer to a USD peg.
'fully backed' is not the reason the peg holds...fully backed means backed by 2x BTSX.
being backed by even 1 BTSX for 1 Unit of value in bitUSD should be more than enough. (and this only happens in fast and huge drop in BTSX).
On a third issue (Probably the most important):
BM have consistently referred to such bitUSD as unbacked - in reality the bitUSD in existence are not individually backed
. So if you have 99 USD backed 100% and you add 1 backed 0 % you actually have 100 bitUSD backed 99%. You do not have some backed and some not.
The reason for that is that from holders perspective you do not hold backed or unbacked bitUSD, you just hold one that have the same qualities as the rest of them.