Is there any reason to think that routers in general - BGP and
internal routers - will be upset by an option header, specifically a
new kind of option header as you suggest?
Another gentleman mentioned to me privately that currently deployed
routers tend to kick any packets with options to the slow (software)
forwarding path since the options might require the router to take
special action. Perhaps its possible to change that behavior with a
software upgrade that offers a configurable to ignore record-route and
timestamp options in favor of keeping IP packets with options in the
fast path.