I own a Framework laptop. Here's how I have it configured. I did this so I could easily reinstall the operating system without having to worry about my data. I then went a step further and made it a multiboot machine.

Framework laptops use expansion cards. It's clever because it allows me to move USB ports to whatever side of the laptop I want them. Their selection of cards includes 256 GB and 1 TB storage. They're fast, high quality, USB drives. I have a 1 TB card.

Inside the computer is a 2 TB NVMe.

The NVMe serves has as my /home partition and is shared across all of the operating systems I have installed.

My 1 TB expansion card has several partitions.

sda           8:0    0 931.5G  0 disk 
├─sda1        8:1    0   487M  0 part /boot/efi
├─sda2        8:2    0    64G  0 part /mint
├─sda3        8:3    0    64G  0 part /ubuntu
├─sda4        8:4    0    64G  0 part /debian
├─sda5        8:5    0   7.6G  0 part [SWAP]
├─sda6        8:6    0 295.4G  0 part /opt
└─sda7        8:7    0    64G  0 part /lmde

Much like my /home partition, my /opt partition is shared across all distros.

If you do the math you'll see I'm using only about half of the storage on the card. I've reserved this for future use.

Does it work? Yes. It works very well. The expansion card is fast enough to run the OS and sharing /home and /opt hasn't presented any problems thus far.