Questions About Reconfiguring Dual Boot Setup

I'm preparing a new PC build and want some advice about O.S. boot configuration.

The current system is multi-boot, with Windows 10 on SSD #1, two Linux distros on SSD #2 and a backup hard drive.
Both Linux distros installed their own boot menu, which I modified for better appearance.
All three of the O.S. are available from both of the menus as well as from the motherboard optional UEFI menu.

Everything, except the Linux SSD and a new backup hard drive, will be moved to a previous case to function as a Windows 10 machine.
There are image and file backups on both of the hard drives.
Both SSDs have GPT partitioning. The bootloader is on the Windows drive.

Is it possible to convert the Linux drive to boot the two Linux distros without having to reinstall?
I'm not sure about what to do with GRUB2 on the Windows drive.
Does it need to be removed? Can I just run Startup Repair from the Advanced Options on the Windows 10 install media?
I have Boot-Repair-Disk on a bootable flash drive, but I have never used it. https://sourceforge.net/p/boot-repair-cd/home/Home/

Reinstalling MX Linux would be easy since I have a remastered installation on a flash drive.
Have not been able to remaster my current Linux Mint installation. I tried a couple of methods, but both failed.

Suggestions?
Thanks.

 

For the Win 10 system take a look at the possibilities of the free version of EasyBCD. I'd be pretty sure it would be able to reconfigure the boot config to eliminate, or at least bypass Grub2. Don't know about the Linux disk as you can't install EasyBCD in Linux. There's sure to be a Linux equivalent to EasyBCD but I have no idea what it is.

 

The other thought I had about this is that dual booting has fallen well out of favour with the capability of virtual machines nowadays. Win 10 has HyperV and our old friends Virtual Box and VMware are both free and amazingly capable and versatile with none of the config issues dual booting can present.