The other option would be to have the ability to stake with non-voting stake into the wallet with the option for a fast powerdown
Actually, that feature always has existed since the beginning. It's just the "saving account" section in the wallet. Whose stake stored there never had influence in the voting system and only requires three days to convert that stake in liquid form again.
In the very beginning in the Steem blockchain, that stake stored there used to earn interests. But after a little while, in one of those HFs they changed the rules and code to turn out the saving account financially useless beyond barely have that stake a bit safer from a potential hack. But then, people seems to not use that section of the wallet anymore basically because of its now financial futility. Despite the extra layer of security against hackings that it offered at the time and still does.