this is a rather old topic, nevertheless someone might be interested in.
LinOTP is not integrated in UCS anymore. When I was working for the company, which provides LinOTP, I was the driving force to put LinOTP in the App Center. It seems that currently no one else does.
privacyIDEA is a modern fork of LinOTP. Modern in regards to python style and the underlying framework.
As you saw, privacyIDEA is available in the App Center. (hm, ok, currently we are working on the App for UCS 4.2)
There might be many reasons, why your were "never able to get it working". In this case, you might ask for help?
First you need a subscription file for running privacyIDEA on UCS. You get it here:
If you want to do SAML, you also need to install the privacyIDEA SAML Plugin on your UCS Domain Controller.
Next step is to got to the privacyIDEA management interface and start enrolling tokens.
You can log in as "administrator@admin" with your domain password.
...just in case you want to give it another try with UCS 4.1.