To be honest it's all down to his manager Keenan Sofuoglo, he's the one that's pulling the strings and obviously taking a decent percentage in the process. There's probably a large get out clause to break away from RB. Look at Dovi he was an RB sponsored rider, now on the Yamaha he's lost a lot of his sponsors, even an unbranded helmet, but I am guessing his stock went down when he didn't have a ride, so getting the Yamaha gig was probably a bigger pay day.
Looks like the closest hes got is just over half a second this morning, very impressive. Whatever theyre testing this afternoon not working as well as hes nearly 1.3 seconds off FQ.