I still don't agree, sorry.
In your example you take relative to respectively the bct reserves and the klima outstanding circulation an equal % amount of bct and klima out. So this doesn't generate value. The fact that 30% of the klima is not burned, while the full equivalent amount of bct is burned makes every klima weaker. That you don't count the 15k klima anymore in your backing calculation is an accounting trick, because you state that they are still backed by the same treasury reserves that are still, in full, part of the backing calculation.
The real effect here seems to be shifting excess reserves from the klima holders to the DAO. There is no real fee charged to the user for retiring.
I don't mean to be negative so forgive me challenging this hard. I want to understand this to be 100% sustainable and positive for klima.
An alternative design could be that if you want to retire for $10000 it wil cost you $10500 (in klima) and of this $10000 in BTC is burned, $10300 in klima is burned to accrue value on the remaining klima and $200 in klima is sent to the DAO for funding further operations and initiatives. Only if users pay real fees to use your product you'll obtain a sustainable model.