DAO already have sources of income like RW, NODES, market fees, and other possible like PROMO sales or other... It also has SPS amount specifically allocated to DAO.
DAO doesnlt need to farm it's own rewards. DAO controls the SPS supply in the first place. DAO farming it's own token doesn't do anything except reducing the emissions to players. DAO farming it's own token, or saying reduce emissions by 80% and route back funds to DAO is the same thing.
It will be better if DAO lock that Liquidity in panckeswap and susi farms to earn cake and sushi. That way DAO will not only have liquidity provided but earn external tokens which can be later used to do anything (like buying SPS, or buying DEC or holding these tokens or selling for stables etc.)