At first thought, this sounded very good. But then, think about the current scenario. If TRON locks up their stake for 1 week longer, this will require the rest of the community to lock up for 1 week longer. It's trivial for TRON to do it but probably extremely difficult for the community.

In fact, TRON can lock up for 1 year and this will give them huge governance advantage. The rest of the community likely wouldn't be able to match that and will lose control over the chain. For TRON, locking up for 1 year wouldn't be such a big deal because they can't sell their huge stake in a short time period anyways. So powering it down over a long time seems like quite a desirable trade-off for more governance power.

Same for any larger stakeholder. The large stakeholder would probably enjoy more influence over the reward pool and governance and SPS proposals in exchange for powering down for multiple years. If they have a good-size stake, they can power down over multiple years and get some good amount of STEEM every week. Whereas the small stakeholder, if powered up for a longer period of time, would get a negligible amount of STEEM each week, so why would they choose to power up for a longer period of time?

Overall, I am thinking such a change will put small stakeholders at a disadvantage.