Once a plane gets down to one pixel in size, we have no control over that pixel size.
That aside, resolution is not really the issue. It is the DPI (dots per inch) which is the issue.
But you did at one point in alpha/beta have the unrendered plane dots as multiple pixels, didn't you? I'm sure I remember something that looked like that.
It would seem to me there should be some kind of formula that could be applied using a baseline something like a 21" version of whatever resolution monitor you've got. A bigger monitor's obviously going to mean bigger dots, but it's already got bigger everything so that shouldn't be much of an issue.
Maybe use that formula to apply to the rendered planes so if say, the dot size was 10 pixels diameter (actual numbers purely from backside), when the plane rendered, if the fuselage was going to be 3 pixels from whatever aspect you were seeing it, it would be rendered at 10 pixel diameter until it got close enough for the normal rendering to take over.
I think it would work, but I could be wrong.
Wiley.