You could design one on blockchain, yes. I can't really discuss the particular merits of it, though, because this RFC doesn't deign to actually address any of

You could design one on blockchain, yes. I can't really discuss the particular merits of it, though, because this RFC doesn't deign to actually address any of the interesting or difficult parts of enhancing BGP. It doesn't even talk about what security properties their proposals would support if they had been written - other than 'more secure'.