Thank you very much for the quick response, Amier! 
I read the document and I understood that, according to the instructions, the Consul servers should first of all be deployed as a StatefulSet.
Unfortunately, in our case, the Consul servers are deployed as a Daemonset - it is a pretty old design (~5 years), so I think we should reconsider this and change to a StatefulSet now, so as to take advantage of the rollingUpdate: partition option during the upgrade.
We’ll check it in more detail and get back to you if I have more questions.
Thanks again for the support,
–Evi