Here are a couple of alternates that you may like and is reasonably close to the $14.8k wire price of the 1.537.
1.601 G-SI1 @ $14,366
Diamond | 1.601 ct G SI1 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4400973ThisA CUT ABOVE® super ideal cut hearts and arrows 1.601 carat G color SI1 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4400973www.whiteflash.com
About $500 cheaper than the wire price of the 1.537 and right at 0.20mm better spread. Double check with on it being eye clean, but I think it will check fine. I might ask them if either feather becomes noticeable as you twist & rotate the stone.
FYI, the 1.601 has a little larger table and shallower depth pushing some of the carat weight in the horizontal plane to increase spread, while still staying within ideal proportions.
Looking at the video, the stone still has plenty of fire so was not negatively affected. However, it's a wise use of carat weight and IMO gives you a little more bang for the buck in that regards.
1.627 G-VS2 @ $15,698 wire
Diamond | 1.627 ct G VS2 A CUT ABOVE® Hearts and Arrows Super Ideal Round Cut Loose Diamond AGS Certified | 4392266ThisA CUT ABOVE® super ideal cut hearts and arrows 1.627 carat G color VS2 clarity loose diamond is graded by the American Gem Society (AGS) Laboratories. | 4392266www.whiteflash.com
For about $900 more than the wire price of the 1.537 you can stay in a VS2 clarity, and that same 0.20mm gain in spread. Aside from clarity, the main differences being this stone has a slightly smaller table and more depth so a little more of that carat weight is pushed in the vertical plane so while it weighs a little more it doesn't necessarily have a larger spread.
One final size comparison. The 1.601 vs the 1.627.
This is extremely helpful! Can't thank you enough.