Detected Unsupported Drilled Slots (oshpark)

[maui]

just as a workaround you can use
kicad-action-plugins
action_menu_annular_check

Annular checking: How do I check if all my pads diameter is drill diameter +0.3 (or so)?

just putting a link here… annular script can be called directly from a button now, using Action Script https://kicad-info.s3-us-west-2.amazonaws.com/optimized/2X/b/bfe71eb0d1c222ad1e6f51c876749e83c3c22394_1_632x500.gif