On our very first attempt to see if the Dell Latitude E6540 would join the number of successful HackBook Systems, we took the ESP contents from the Dell Latitude E5440 and attempted to boot it without changes since doing so was successful on the larger Dell Latitude E5540. It did not take long for us to see that this was a mistake.
After taking some time to review the verbose mode output from the first attempt, we saw that we needed to rebuild the EFI folder from the ground up so we did and then went for a second attempt. This attempt turned out to be 99% perfect due to one of the installed kernel extension which caused an issue with the fresh installation.
If we had installed macOS to the boot storage while it was connected to a desktop Mac in one of those SATA to USB enclosures, we would not have had this issue since the EFI folder supported booting but not installation so that gave us a chance to find a potential bug before release.
Fortunately, finding the kernel extension would not be difficult as the kext is being used on the Dell Latitude E5440 so the kext was copied and then imported for a third attempt. The third attempt to install macOS Sierra was a success and the System Software is installing. With the installer now working perfectly, our fourth attempt is to configure an account and check for any issues and correct it during post installation.
With everything running great our fifth attempt is to see if macOS High Sierra is compatible as the user mentioned that they were interested in installing Final Cut Pro. During the upgrade, there were some minor to major graphical issues but as you can see in the sixth attempt, it did not cause the upgrade the crash. As newer release can drop support, a seventh attempt is planned see if there will be similar issues with macOS Mojave.