[horde] Horde 4 migration from 3 - what should we expect?

[D G Teed]

I did the webmail-install step and pointed Horde 4 to
a copy of our Horde 3 webmail database in mysql.

Afterward, I visit the configuration setup as an admin
user of webmail and I get green indicators for all applications.

In Horde webmail portal, I don't see the blocks I had set up
in Horde 3.  Is that expected with this major upgrade?
Will users need to set up their horde portal page again
or is this an indication something didn't work with the
upgrade?  The webmail-install script doesn't give much information
about what it is doing - I think it might have even said
"installing tables" rather than something like "upgrading schema".

I'd like to see a guide on upgrading which has the focus of
how to upgrade and migrate with little downtime for users.

I typically set up a newwebmail.example.com, running from a
copy of the previous version's database, and tweak it
for some days until I'm ready to roll it out.  The problem is
if people have updated their apps with fresher
data in the meantime, it is lost when I switch newwebmail.example.com
into webmail.example.com (production).

I can't dump the production Horde 3 DB again and
refresh the Horde 4 DB after doing setup and tweaking config php files,
or else the settings are lost and Horde gets confused.
Some settings depend on a hybrid of config php files and
database values which need to be changed through the web site.

I feel Horde has not focused enough on supporting the installation
for existing deployments, while we are probably the largest
group of Horde users.