So far I've read the rules as being a rider not being already named as a 1-7 in another team line up, and with a 3.00 average, so it means only unattached and/or new riders. With all the talk of having a squad, having an eligible no.8 would be the simple extension of this new suggestion, plus make the rules a little bit more flexible upon whom can be a no.8. E.g.(a rider with a higher average, maybe a 4.00.)
It would make it more competitive to have a decent no.8 in case of team injuries throughout a meeting, which unfortunately does happen. In addition, they'd more than likely get used in a meeting to take eligible r/r rides....just a thought.