Yes, it is not good. Search the forum as there are several recent local X5 examples including similar cars available now via trusted brokers. You should be at minimum 17% discount before incentives on a X5 loaner especially due to the reduced RV and lack of $1K CCA post sale rebate. Does the MF assume MSDs? standard is .00177 but you didn’t specifically mention MSDs.
Ok, that MF makes sense and is not being inflated. But 11% off a loaner is terrible, but there is also limited stock, especially if you want the driver assist package. I had multiple dealers offer 17% off with limited negotiation and got 1 closer to 19% for a X5 loaner. Someone just got a 2019 X5 for $689/month via @stellarauto so wouldn’t even entertain this.
I think your RV is technically lower than 56% due to the mileage penalty.
Join BMW CCA for $130 for 3 years and submit the rebate through their website post purchase. X5 is $1,000 so you net $870 but can take 12-16 weeks to be proceed. Loaners do NOT qualify.