The canvas JSON function added last year will base64 encode images and media. We don't have a way to convert other data types to binary, to then be base64 encoded; if there is more need here please tell us more about your scenarios.
@archanan to update status.
Adding @archanan to confirm status pls.
@archanan to confirm status pls.
Adding @archanan to confirm status.
If you are referring to connections to SharePoint Libraries, this is planned. We do not have a release date at this time but will keep you posted as the feature release gets closer.
Thank you for your patience and continued feedback,
Audrie