I don't see how the current power-down timeframe is a problem. Staking should be a serious decision. It includes governance power, vating power, and so forth. Reducing liquidity means giving up on playing the crypto-bro trading game in exchange for ownership of the chain, and should be a major choice. Do you want skin in the game or not?
The old 2-year process was too long, and had a chilling effect on willingness to stake. Imagine being trapped in STEEM for 2 years after the Justin Sun coup.
4 weeks is probably far too short, unless perhaps it were instead 4 weeks of daily pwerdowns instead of 4 chunks.
13 weeks, or 3 months, is quick enough to liquidate savings at a steady rate while ensuring at least some time horizon for decisions.
Those who want liquidity can choose 50/50 payouts on posts and not stake.