1)He could improve scalabitlity with
- 3 Mb Block size
We already have a 4MB block weight limit.
Further capacity increases would just increase throughput. They would not improve scalability.
2) He could improve TX Time and savety by set up Masternodes with an reward of 5% of every block. This would not be really POS if you dont like that
It
is a form of POS, if only a hybrid form.
There is a long list of potentially desirable hard fork changes to Bitcoin called
the "Hardfork Wishlist" -- hybrid POS will never be on it.
3) He could make himself quantum resistent
That could be done with a soft fork, like the implementation of Segwit's signature scheme.
There will never be enough consensus for a hark fork other than a catastrophic technical problem. There are just too many competing interests and agendas. All attempts to force it have failed and as time goes on it'll become ever less likely.
In a few more years the thought of it will seem as outlandish as voting to get the sun to rise two hours later.
Basically. The market has spoken pretty strongly about this: A Bitcoin hard fork = a network split.