Nice idea, but when the bar code reader stops working (as it often does at my local parkrun) it take a helluva long time to write down that 8 digit number. Not so bad at the end of a parkrun, but would be a right pain at ne of the checkpoints in an AL.
One thing to remember though, is that these changes are a DRAFT for comments. How many have actually sent their comments to the FRA instead of/as well as airing them on here?