I'm not 100% sure on this yet but I think I might have earned 11.5x on a recent hotel booking.

I booked a hotel a few days ago intending to take advantage of this offer so did a search for hotels via my CFU hotel portal. However, it was late at night and without realizing it I ended up actually paying for it with my Reserve. As this hotel is only for two nights but during cherry blossom season in Tokyo I decided to just leave it as availability was getting very slim for my dates and and I didn't want to take a chance on cancelling and rebooking.

As expected, I see 879.48 points on the activity list for my CSR ($293.16x3). However, in addition to this the "Earning on next statement" on my CFU went up 2492 points and it is listed as pending under the Bonus earn at the bottom of the CFU page.

If this goes through then maybe you can get as high as 12x by using the CSR through the CF's portal?