Hi,
We have recently upgraded our octopus server from 3.2.23 to 2018.1.4.
I have already posted some of my observations on octopus help forum (below url) and still waiting for the answers.
In addition to the above, we are also in process to have multi tenanted pattern in our projects, but we find it a bit difficult to enter the values in tenant variables for templates defined at the project level as variables per environment cannot be collapsed and they are spaced a bit liberally. As we have four environments (DEV, TEST, STG, PROD), so for a tenant for each project we have 30-50 variables per environment making it 200+ variables on one page.