Delta Chat does not have delivery receipts.
The only kind of invisible automatically replied messages are part of SecureJoin. If you show someone a QR code or give them invite link, then your device needs to process requests for the keys (vc-request/vg-request) messages before 1:1 chat is created or before you add them to a group.
Users who never don’t have your invite link and have not scanned your QR code, e.g. contacts that are just in the same chat as you or who got your contact via someone as a vCard cannot check if you are online this way.
I have opened Prevent silent probing of device online status · Issue #7555 · chatmail/core · GitHub with technical details.