I strongly disagree that you want to make Yelich a full time DH and demote Hoskins to a platoon role.
I don't think the improvement in defense with Frelick in LF over Yelich justifies having his bat in the lineup every day. Plus, the Brewers need the flexibility to use the DH spot to give Contreras days off from catching occasionally.
Even though he's been slumping lately, I think it's way too early to throw Hoskins onto the platoon scrap heap where he might just play once or twice a week. He's a veteran player who has shown that he can get hot.
As my preferred lineup for one game against a RHP I would rather have Yelich in LF with Hoskins as DH and Bauers at 1B. Frelick can still play a few days a week to give others a break. In a given week I could see Yelich, Hoskins, and Contreras each being DH a couple of days or getting a full day off.
One thing for absolutely sure is that there will be some more injuries (even if they are minor) that will open up spots for others to play.