Also used the delay to stash some more

And yes PoS is not a panacea, it removes the issue of Multipools jumping and dumping (the jumping being probably the most annoying, dumping reflects that you can't secure a network for free), but PoS moves the onus of security to all Noble stakeholders, for them to stake as much and as often as possible to secure the network.
From recent experience, it's very easy for a PoS chain to err and fail if there are few servers staking (as in 24/7) vs just wallets on PC or Macs (often offline, or with limited connectivity). So people need to stake, this means not just a high enough interest but also an incentive to stake all the time, maybe through limits in stake age (not the maximum age of the transaction, but the maximum age taken into account for the interest).
Ideally a wallet staking 24/7 should get higher rewards than a wallet coming online once a month, and that's not always the case depending on the staking parameters. In practice, big wallets coming online just from time to time can fork the blockchain if there are not enough other stakers online, especially if they have poor connectivity (like a home PC on a wifi with a sluggish ADSL... or worse).
Making a PoS blockchain safe is simple and cheaper than PoW, but it still requires for the stakeholders to care.