I purchased a 2 tb micro as card off eBay for $40. Formatted it to fat32 and it works in my Sony Xperia 10ii on sailfish 4.3 and is recognized as 1.9 tb. Originally bought 2 tb because that is the fat32 limit.
Fat32 is the most universal but has a 4gb filesize limit. What other formats are supported by sailfish that doesn’t have the file size limit? Had issues with Mac journaled the other day when I tried it. Maybe it was user error lol