You can redeem Avios points on FLYBE routes, including NQY-LGW JER/GCI-LGW ABZ-LGW and INV- LGW.
Interestingly, NQY-LGW-GCI RTN is only 9,000 plus fees. / saver
I know because I have booked all of the above!!!!

I have two Avios accounts.... the former Airmiles account and my BA Exec Avios account.
For whatever reason, you can book FLYBE using the former Airmiles account, but not with BA exec Avios, despite the LGW-INV flights also carrying BA flight numbers.