Add a warning or note on the vault export page, that attachments are not included in any export. While speaking to Bitwarden about an issue I was seeing, they suggested to export, purge the vault, and re-import. While that fixed my issue, an hour or two later I thought about the attachments and sure enough when I checked they weren’t included in the .json export. Luckily I was able to restore a snapshot of the data folder, but unfortunately this leaves me stuck with the unrelated minor issue I have.
This is probably better suited to be asked at Bitwarden since they build the clients used by Vaultwarden. Feature Requests - Bitwarden Community Forums
Makes sense. Thanks.