exFAT is a newer and viable alternative to FAT32, with better size limits and some pretty good cross-platform capabilities. That said, if your primary access is through Windows, NTFS may have some better features and is at least read-only on other platforms.
As I understand it, their data does in fact enter into the Wayback Machine. They are just also available in the direct WARC archive files(which IMO sounds beneficial to the idea of exporting in bulk to another backup host). At least that’s how their FAQ reads.
And given that they focus on web crawling, and not other arbitrary data formats that IA accepts, 2.8% of over 100 petabytes is still a respectable amount of data.
That said, help is help. If another archival project team wants me to run a worker node so they can distribute load and dodge crawler blocks, let me know, I’ve got space.
This is why I can’t/don’t have a lot of the “best practices” in my family archive. I’m not encrypting local drives, I’m not using BTRFS, or a ZFS pool. If I did I’d have to ensure my Will provided for the lawyer to hire a tech shop to help recover them. No, exFAT and NTFS, in the clear so those left behind can just plug them in and get to making their own copies. Otherwise the archive would die with me.
Does that mean someone could steal my drives and go through my family photos? Sure. I hope it brings them much guilt, something a garbled encrypted drive could never do.