I'm somewhere in the middle of supporting this and not. This all seems to me to be a mix of a stock buyback and the formalization of the DAO as the Central Bank of DEC. Very interesting and fun stuff. However, I'm definitely more in the "no" camp due to a few reasons.
Why use all the stable coins? Perhaps only use 20% and see the impact. Based on that impact, we can make some extrapolations before using up all the stable coins in the DAO.
The effectiveness of doing something like this should be somewhat empirical. I haven't pulled all the on chain metrics and done a deep dive on the tokenomics of DEC to tell you exactly how to go about this, but based on the current DEC demand and supply, we should be able to figure out the impact and if it's meaningful enough to carry out ahead of time. At the very least, having the hypothesis and testing against it is useful. For anyone interested, I would start with using the Equation of Exchange.
If it goes through, how will the DEC be repurchased? Is it one market order on a DEX? Or two on Uniswap and Pancake? Or three if you throw Tribal Dex? Carrying out a trade that you know will move the market is a different animal that topping off your DEC holdings. Having some clarity on how the purchase will be carried out would be useful and ensure if all the DAO stable coin funds are used, they are used as effectively as possible.
Also - why the hell aren't the stable coins earning some yield somewhere? Curve perhaps?
RE: DAO Proposal: Swap DAO BUSD and USDC/T For DEC