Question: Guacamole App upgrade to latest using docker

An early version of Guacamole is in the App list and still can be used.
It is integrated to the Univention infrastructure very well, can be managed from UCS.
I already tried and it works more or less (technically works well).

As this app uses Docker, I assume it would be relatively easy to upgrade the version 0.9.13 to 1.5.4.

My question: is that possible to upgrade the Guacamole App by Univention in the App Center?
What is the reason, if any, it kept on old version?

I played with latest guacamole in docker on a standard lxc container, which joined to the domain using univention’s join scripts. This script only joined the “machine” itself, not guacamole.
I reverse engineered the official App (I am stupid, I will check github, somehow I forgot to check there) installed to an UCS server and I started this new version of Guacamole to connect to the ldap server, which seemed working: I am able to authorize the user to the ldap, but the registered connections do not show up, so, I am not able to connect any of my existing connections.

As the UCS already could have backup etc. instances, technically not a problem to install a new UCS which serves only Guacamole, so, to have a fresh guacamole could be useful.

Any hints?