Watching close.
Kicked my self when we remodeled the bedroom, should have installed ultra fin then, didn’t hear of it till years later.
Still have the office to remodel, it shares a wall with our bedroom, I’m thinking place the pex, staple a layer of ply foil over the studs then cover the office side in drywall. The ideal of placing registers at the top and bottom also has merit. Fire stops are already in the walls and I tend to leave em, so only the bottom half of the wall would get heat anyways, I’d also stay at least a foot off the floor as we have the tall baseboards.
If it works may redo the upstair bedrooms the same, a lot easier than tearing the floors up to place ultra fin in the joist bays. Ain’t tearing the downstairs ceilings out just to install radiant, those were all over lays anyways as I wasn’t about to pull lathe and plaster down in my face.