Part of the problem here is that Neville is thinking and writing in terms of wheel circumference, while almost all of his potential readers are accustomed to thinking in terms of counts per kilometer. The two are readily equated, but only with extra mental effort.
Also part of the problem is that we have not yet seen a simple, step-by-step description of the process. I took a stab at it but may have it wrong.
As I see it, pressure vs circumference data (or counts if you will) are used to determine the final constant. While this may approach the accuracy of a direct calibration, it is not quite as accurate. It may well be good enough, but we lack experience to judge this.
I’d be inclined to accept a measurement with pressure-determined postcal, but only in a case of dire need. If a remote calibration course is to be used, it’s likely one close to the measurer’s home. This given, there is no reason not to do a direct postcalibration. If an adjustment is required, this can be conveyed to the race director by telephone. I’d be disinclined to drive 80 miles to move a start line mark 16 feet.
I think the proposed method is ingenious but unproven and risky.
Last minute brain spasm: Couldn't the method be used to replace precalibration as well? If it's good enough for postcal, why not precal?