DB2HOST variable needed for PureScale to redirect and define IP to participating subnet's

In Db2 PureScale GDPC the Db2 cluster is distributed on 2 different physical locations and a Quorum Host (tie breaker node) on a 3rd location.
The general Db2 install routines use the 'system hostname' (gethostbyname) for the ongoing install procedures. For Db2 PureScale the 'system hostname' is also forwarded to different products like Tivoli SA MP (TSAMP) and SpectrumScale (GPFS).
On our environments the network infrastructure is designed to distinguish the different network locations by using different subnets. The 'system hostname' is reflecting an (relatively slow) internal network segment which is not routed to other locations. The host however can be reached by using routed other high performance networks, so called 'service network', by using a 'hostname-p1'.
This network layout makes it impossible to use the TieBreaker for PureScale because DB2 enforces to use the 'system hostname' for communication. This is impossible because in our environment the 'system hostname' reflects the internal/local network, and cannot be used for communications to other plants.
We require a possibility to direct DB2 using a predefined IP -Address/hostname, for example by implementing a 'DB2HOST' registry variable, so that the automatically taken 'system hostname' can be overwritten by explicitely defining a hostname/ip-address which should be used instead, and which is able to communicate to all participating subnets in all participating locations.
Salesforce Ticket: TS001313467