I have an enclosed "trough" under the roof, with lines plumbed similar to yours except no PVC.
I'm thinking of re-doing my setup to build a trough on top of the roof, not under it. I really dislike having to do any maintenance on lines jammed into a trough above me. I'm high up on a ladder, at first fighting with the cover to get it opened up. Then when I do, some insulation invariably falls out and down, usually on me. Then to troubleshoot or do a repair I'm reaching above my head while balanced on the ladder to unscrew anything that might be leaking, like a fitting, or replacing something like a backpressure valve. I can do it, but I'm tired of it being overhead which makes any such work more difficult.
I'm thinking of changing all of it out to a roof mounted trough. If I had that, I could be standing on a roof, open a top hinged piece, and have access to everything without having to reach up or have insulation or liquids spraying onto me.