Vertical T&G over comfortboard, screwed to sheathing?

x posted on the GBA q&A but realize this might be a mire suitable place:
Doing what I can to air tight our 1976 rancher reno.
Dealing with 2 small areas of siding that are different to the rest of the house. Window bump outs that have 1″ comfortboard over 1/2′ ply sheathing.
Sheathing has Vycor Env-s peel and stick WRB applied.
From an aesthetic perspective, I’d ideally like to install 1×5 VG themally modified hemlock vertically. Just to soften the hardie panel and corrugated mix on the other walls.
The vertical install is the crutch here as while the windows are bucked out 1″ to match the comfortboard, I don’t have enough room to add sufficient furring to give a “solid nailer” as I have to meet pre-installed hardie flashing as each wall corner.
Whilst the comfortboard is “free draining” my plan is to add 0.25″ Keene driwall with integrated WRB over the comfortboard for airgap then fasten the themally modified hemlock with stainless steel trim head screws through the entangled mesh/comfortboard into the 1/2″ sheathing.
The only guaranteed structural screw backing would be at the rim joist and top plates.
Sure blind nailing would be preferred and horizontal far easier, but I know how i prefer it look as a finished wall and whether face screws are a suitable solution is the question.
I’d welcome any thoughts.
thanks!
Replies
You could try pre drilling the boards through the tongue edge at an angle with a painted head screw. I've seen an ipe porch floor done that way and the heads didn't get in the way despite protruding some. You just need a light touch to avoid splitting. Maybe even drilled with a trim head countersink? Longer screws of course, but that might be a good idea anyways 3/8 isn't much room for error and being shallow by a bit doesn't give much if any thread engagement.