upgrade from Mariadb 10.2.* to 10.3.* using mariabackup? Anyone successfully done upgrade from 10.2 to 10.3 using mariabackup without any downtime to the cluster?

I have 3 node cluster. Node1 serves the traffic rest are for standby and quorum. I would like to upgrade them from 10.2 to 10.3. 

10.2 -&gt; Has xtrabackup
10.3 -&gt; Has mariabackup


IST doesn't happen when I upgrade 3rd node from 10.2 to 10.3. But when I copy xtrabackup* files from 2nd node and use wsrep_sst_method=xtrabackup_v2. IST works. 
When I change it to mariabackup and restart it doesn't work.
This is not what mariabackup is for. You backup and restore in the same "major" version (where "major" means it just means first 2 number of the version). If you need an upgrade, this is what mysql_upgrade is for.