Love the idea and appreciate how mStable has been a consistent and long-time partner of Balancer (since the early days of our V1)!
BTW I’m also really interested in your implementation of the Gauge controller as this could be one of the foundations for the implementation of Balancer’s BPT locking mechanism already approved by governance.
Regarding the 3 options, I would probably lean towards the DAO<>DAO token swap as it’s probably the simplest/cleanest and we have recently the precedent of other such swaps that were well received by Balancer governance.
Curious to hear more opinions =)