I wouldnt eliminate PoS completely, if nothing else it will help promote Slim as a coin with a trinity of ways to mine/mint.

PoB should always be the star of the show because of its perks over older Proofs-of-X. It brings mining to a whole new level by completely skipping the part where one gets shafted by pre-ordering a "fully QC tested" rig 

Investment ---> Return, nothing in between