Reading the wording on Rising Stars you could be right as its around the 2024 season and doesn't cover past seasons. Common sense would mean a rider who has progressed out of the RS isn't allowed to drop back in it. My personal opinion is all riders 21 and under should be able to be a rising star no matter their average, and up to and including 23 on an average below 4 (moving our of the scheme for good once this average is achieved).
I think (I could be wrong here) but your averages will have meetings missing as they only include August up to and including 23rd. The averages I have used are the season ending totals after Ipswich and Birmingham's last meetings on the 29th August.
Knowing British Speedway point 1 wouldn't surprise me, but how crazy would it be if he's allowed to drop down again.
Point 2 this is what i get
Doyle: 9.36
Emil: 9.12
Rew: 5.79
Ellis: 5.47
Brennan: 6.59
Thompson: 3.10
Total: 39.43
Jenkins cant be a rising star, the rules state once a rider achieves an average of 4 they will no longer be eligible to be a rising star, so he cant go back.
Also what averages are you using as that 1 to 6 comes in at 39.43.