Just to keep everything in one config I'll post this here. Just some things I've noticed that are not functioning in the Debian 10 support as of yet.
1) The support tab gives an error
2) No matter reinstall, reconfigure can not get spamassassin plugin to install. Gives error about roundcube config missing. Comparing to a debian 9 with stable release imscp the /etc/imscp/roundcube and /etc/imscp/rainloop directories are missing in debian 10.
3) During install enabled backup features for clients and panel still shows backups disabled.
4) Creating an email foward seems to fail with account already exists. But you can create it with normal and forward and it will create fine.
5) Cron jobs plugin fails with error invalid plugin archive. the build plugin info field is missing
Will continue to test and see if I find any other issues.