Yes, I understand this point. LMDE is the backup plan, but is it actually inferior to regular Mint based on Ubuntu? If not LMDE could be default Mint.

If your current distro works, there’s no reason to switch. Switching means a fresh install, repeat whatever customization you want or need, restore your backup. It’s not difficult, but can be time-consuming until you have everything configured they way you want it.

I wonder why they make both Ubuntu and separate Debian based Mint. That duplicates the work.

I would probably jump from ubuntu to mint if they drop ubunutu in favor of debian. But then, debian itself is a perfectly fine distro and i could also use it directly.

Too much choice.