Your last benchmark mentioned that this was a test for Windows 10. I may have missed this qualifier in the previous discussion: do I take it that the slowdown in performance noted are all Windows 10 tests? Has performance on Mac and Linux also degraded by similar amounts?
I ask because of the earlier discussion of the drastic slowdown in saving a stack under Windows 10 [bug 21305 <https://quality.livecode.com/show_bug.cgi?id=21305>] (from x10 to x30 longer than on a Mac or Linux box). This applies to LC 8, and is a comparison between platforms rather than versions of LC, but if the answer to my second question above is no, then it would particularly direct attention of the engineers to the Windows engine.
BTW, just for interest I ran the repeat loop benchmark in LC8 on my Mac, and then Windows 10 and Linux Ubuntu 16.04 both under Parallels emulation on the same Mac. As expected the Windows 10 run was a little slower (about 12% slower) than the Mac 64 bit test, understandable given it is running in emulation. But the Linux run was about 10% *faster* than the Mac!!