We resolved this for @DracoBlue. It looks like the way we measure disk space for rendering in the UI takes into account filesystem reserved blocks (https://wiki.archlinux.org/title/ext4). We calculate the total space less the available space and display that as the usage. If you are running ext4 and you have a large filesystem, the default reserved blocks are 5% of your total file system size which is why the usage appears so high.
This space isn't used by Enhance. You can verify this with du or dh. You can adjust the reserved blocks with tune2fs but I wouldn't recommend this unless you fully understand the implication.
We will improve the disk usage display. We may be able to display reserved blocks as a separate value.