Well, the big reason is enhanced usability. There are only a handful of DAV servers and even if they do change the address and don’t let you know, the long address will still work.
This would be true if there would be no better methods to detect the DAV paths – but there are And these will be implemented.
can in owncloud maybe .htaccess rewrite-engine be used to follow up the standard?
Indeed, see http://doc.owncloud.org/server/5.0/user_manual/pim/troubleshooting.html
(Actually, it’s not “Troubleshooting”.)
Yes, I agree with that, but I’m not good enough to know an other way to get a such good management of authorisation.
Maybe an other caldav/carddav server is listing all accessible collection by a user in its own collection as virtual calendar maybe, but I don’t know a such server.
I agree what I’m asking for is for advanced user and configuration. That’s why my patch on the fork I’ve done keep the default way of working of davdroid, but it could be changed as davdroid suggest a premptive login mode.