FWIW, Serr, I've been using FileVault for years, also on disks that are used for recording. The performance loss isn't even noticeable.
But, yes, it shouldn't be enabled by default. And there's a worse bug in there. In some circumstances, it resets your FV password. If you don't have the secondary unlock key, your data is toast...
That reminds me I should backup. It's been a while