Hi,
Good post, I have discovered it only now …
In my case, Android to /e/OS:
Contacts : I exported from old Android device by creating a .vcf file (as vCard was a standard backup option from the menu in the old Android) in the micro SD card. Then I made /e/OS import the contacts from the file. Feedback: easy and straightforward, it worked like a charm.
Calendar entries: I did not find any way to export easily, therefore I resorted to manual entry on /e/OS Feedback: sad
Photos : copy - paste to micro SD card, and then to /e/OS. Feedback: easy.
SMS : I did not find any easy way, I resorted to an app called “SMS Backup +” (if I am not mistaken). Feeback: easy with app, but I was disappointed not to have found another way of transferring the SMS
Whatsapp : I followed the different guides of the forum and in the end, I managed to transfer the local backup from Android to /e/OS. Feedback: it worked, but I have a vague memory that it was not that so easy and short…
That’s all (I do not use the smartphone for other tasks). I would be interested in knowing if there are other ways, in case I have to re-install… or if the best solution would be a full backup (how?).
Thank you