I’d propose to enable “Send copy to self” by default. It is mandatory for a multi-device setup anyways and I actually do not see any disadvantages so far.
A multi-device setup without unnecessary hassles.
You have to enable “Send copy to self” on all clients first, otherwise sent messages do not appear on the other devices.
EDIT: With the option disabled questions like this arise: iOS: Same account, two devices: sent messages not synced
Also users with that problem might just deinstall DeltaChat again, because “it does not work as expected” without asking in the forum first.