Hi Stefan - We have configured UDMS in our landscape and I don't see any big impact in terms of system performance so far.( We are on 7.3 and all our scenarios are ICo's)

On the other side for the PI release that you are currently on(7.11), has some limitation for the productive usage.

Have a look at the below notes from SAP:

PI monitors in NetWeaver Administrator not supported for production scenarios

PI monitors in NetWeaver Administrator not supported for production scenarios. This includes the user defined message search functionality, e. g. the search for payload attribute values; the lean message search is therefore not supported for production scenarios, and this includes the configuration of this functionality as well as the monitoring at runtime. Starting with Support Package 6 for EHP1 for SAP NetWeaver PI 7.1 the user defined search can be configured in & used for the integration server ABAP client. The SAP NetWeaver Administrator for PI is not supported for use in production scenarios. Not all PI monitors from the Runtime Workbench are completely integrated  into the SAP NetWeaver Administrator for PI. SAP recommends that customers use the Runtime Workbench for PI monitoring in production scenarios and would not support the installation, configuration and usage of the SAP NetWeaver Administrator for PI.

Reference : 1247043 - Release Restrictions for EHP 1 for SAP NetWeaver PI 7.1