Whether an intermediate box switches out or not is irrelevant to how many sections are controlled by adjacent signal boxes. If intermediate signal boxes are switched out, the block sections are merely lengthened, not doubled. The number of sections remains the same except when the closure of a box shuts a running line completely such as any running line that terminates at the closing box.
It is also misleading to simply count the instruments as they can be single or combined units. The best way of counting the block sections is to count the number of needles (or whatever other type of indicator is used). However this isn’t perfect either as some non-passenger lines can be worked on various forms of the 'No Block' system but these are definitely still regarded as block sections!
Also, in my opinion a single or bi-directional line should always count twice. A single line terminus with conventional block instruments would be provided with two needles; one for the up and one for the down.