Ubuntu as a whole is not licensed under the MIT license, but your scripts to modify it could be (assuming that you're the copyright owner of those scripts).
You can redistribute your custom distro, but you cannot call it Ubuntu or use Ubuntu in its name without permission from Canonical legal. Without that permission, you'll probably need to change a lot of the branding so it doesn't identify as Ubuntu. For instance, /etc/os-release
I am not a lawyer nor do I represent Canonical for legal questions.
If you're looking to clone a drive. I would use clonezilla or borg
If it's windows then well, you're probably asking the wrong subreddit.
That's a bit odd. rEFInd doesn't need GRUB, it can boot the Linux kernel directly. In fact, one of the first thing I do when installing a new Linux is to install rEFInd and then purge GRUB so it doesn't have a chance to get in the way.
Not sure where you got your copy of rEFInd, but since you're running Ubuntu the best bet is to enable the ppa and get the package directly from Rod Smith's website. rEFInd gets updated infrequently, but when it does the changes will show up there, first.
Scroll down the page until you get to the "Getting rEFInd from Your OS's Repositories" section, then follow the simple directions for adding the rEFInd ppa to your repository list. Then reinstall rEFInd from there.
And, of course, after the install remember to get into the EFI setup and point to boot selector to rEFInd as the first option.
Apologies for bombing you with messages, I'm just adding things as I think of them.
Given that this us very new hardware, perhaps a newer kernel is in order? Grab the latest none RC kernel from the mainline PPA and if that doesn't fix you then try the latest RC. Here's some instructions for getting a handy GUI for managing kernels. Don't worry, it's very easy.
https://www.omgubuntu.co.uk/2017/02/ukuu-easy-way-to-install-mainline-kernel-ubuntu