Background
My home has vinyl siding installed over the original Masonite/hardboard siding. The vinyl siding wasn't installed correctly (don't caulk your J-channel, folks, or the nailing flange becomes the weep holes - into your home!) and it led to some massive rot around the foundation of my house. I wound up reframing the bottom half of my house it was so bad.
During that time, I had to remove the windows (because the framing around the windows had rotted away) and needed to reinstall them. However, the rot was only on the bottom portion of the house. I didn't need to remove any more siding than the bottom 6 feet. However, I needed to remove ALL of the siding, including the Masonite siding, to get at the sheathing and studs, and all of the Masonite siding was rotted, too.
After removing the Masonite siding, I was left with a problem. The new windows had a built-in channel for the vinyl siding, but if they were installed flush to the sheathing then the vinyl siding wouldn't terminate correctly because the rest of the Masonite siding had built it out too far. I could have removed the Masonite siding from the entire house (this is really what I should have done), but the entire process was exhausting and I didn't really have the time to re-side the whole house, so I used some pressure-treated material to build the wall out an inch:
My concern with just leaving the Masonite off was that it was still on the upper 10 feet of the house, and it'd cause the vinyl siding to "suck in" along the bottom 6 feet. I used the pressure treated material to build out around the windows, but I used rigid foam insulation to build out the bulk of the exterior wall, after wrapping the sheathing with Tyvek.
Now I'm to the point that I'm ready to (have time and money to) replace the vinyl siding, but I'm stuck with the decision I made previously - I could pull all of the windows, remove the P/T lumber, and re-install them, but it's too costly at this point to do that.
My major concern is with rot or water damage between the rigid foam insulation and the house - I just don't see how the wall section would ever dry if (when, it's always when) water manages to get behind the rigid insulation.
Question
I was wondering if it could be possible to strip the Masonite siding off, install pressure treated furring strips, and install the siding attached to the furring. I had originally dismissed this idea because I was worried wind would get behind the siding and rattle it, but then I saw this ProTradeCraft video where they're installing 1x3 furring strips with the intent of standing the siding off.
I used 5/4 pressure-treated decking when I built the windows out, so it's actually a 1 inch thickness, putting me about 0.25" further away from the wall than the ProTradeCraft video. Would this be okay to do?
What is an acceptable gap between the siding and the wall sheathing?