Cross post with laundry.

My laundry area is a 102" (H)" x 36" (W) x 32" (D) closet which for twenty years has served me well with two stackable W/D (a GE, then the infamous first model Maytag Neptune FL, now twelve years out and still ticking except bearings failing).

I will be replacing the Neptune soon with a new stackable SQ from which I hope to get many years of service.

We pulled the Neptune out yesterday to prepare the space (clean, prep, new paint etc). I am debating what to do with the rear closet wall. Years ago in a very cold freeze, a pipe burst and was attended to by myself immediately through basement WD water turnoff. Since then I have insulated each new pipe with rubber foam, the inter stud wall with fire rated batting 3.5 inch thick insulation, put on new gated washers, replaced stainless covered hoses every five years and changed out venting hose for lint as well as check function of outside damper twice per year.

The back closet wall is partially open where the hot and cold pipe(s) come up from below and waste venting hose rests. I left it this way so plumbers have easy access to both pipes, water return and faucets. I just changed out the washer/dryer gate faucets in the basement (not closet) to ball valve (also did the main water gate to ball valve). I'm want to ensure limited hammering- there is some since this change out of basement pipes and gate valves curiously. Might need to secure those new basement pipes tighter with brackets to wood. I'm adding Sioux Chief mini resters on both cold and hot faucets in closet: I've got the vertical space.

I believe some fire graded dry wall covering this is on point now. I would screw or nail it to studs. Does anyone know what grade is recommended or have any suggestions. The aperture is 30" h x 36" w x what ever depth of dry wall is chosen. I prefer function over form, and think a partial finish back wall which allows removal and attention if needed is better than not.

Anything I might be missing or any suggestions on my idea? I'm a KISS kind of person.

Thank you very much in advance.