Grub Customizer VS Grub2Win

Grub-customizer hasn't been updated in 3 years, I wouldn't let it near my config with a ten foot pole. - Source: Reddit / over 1 year ago

If you can install Ubuntu packages, https://launchpad.net/grub-customizer might do it. Its a GUI to edit grub entries, seems easier than switching bootloaders to me. - Source: Reddit / over 1 year ago

Grub-customizer is supposed to be maintained on Launchpad Https://launchpad.net/grub-customizer But the last version of the package was released 2018-10-13 and the main developer only responded to 1 bug report this year - but it is confirmed to work on Ubuntu 19.10! - Source: Reddit / over 1 year ago

Otherwise, what you'll have to do is image a USB drive with a partition management software or distro (e.g. GParted Live), boot from it, and then resize your partition from there. This does carry more risk of data loss than the dual SSD method, but it's more universal (you haven't mentioned if this is a laptop with more than one removable storage option or not, for instance), and it's unlikely to cause any harm.... - Source: Reddit / 4 months ago

I have a suggestion, follow the previously advised installation process to install CrOS Flex on a separate drive, then reconnect and enable the Windows disk through the boot menu, once back there you can install a GRUB manager under Windows, like Grun2Win, it's easy to install and set up, once you are all done, the final result will be easier to switch from one OS to the next, instead of every time going through... - Source: Reddit / 7 months ago

When using Opencore for booting Windows 10, causes many issues. Even it causes issues when you boot MacOS after restarting from Windows 10. So Fix is Simple Use Grub2win as main bootloader and boot Windows or Opencore ( Chainload opencore efi file) from there. I am available for your queries and help. - Source: Reddit / over 1 year ago

However, I have used this https://sourceforge.net/projects/grub2win/ I install it on the windows side and configure it. It will enable me to choose ubuntu> Ater booting in Ubuntu, I do grub install. If that's too complicated to install grub repair when you boot into Ubuntu and run it. - Source: Reddit / over 1 year ago

On Windows, you might want to try Grub2Win to configure your grub. It should work fine unless you try it with arch distros, but since mint and mx are debian based, you should be fine. - Source: Reddit / almost 2 years ago