The logic behind this is there is no way for eHealth to be able to identify if a community string it is using/accessing is actually RO or RW. We then populate the RW field in the eHealth config by default specifically because there are certain types of elements (like response paths) which require a RW string for the SNMP set operations.
If you only use one community string it will be populated in the RW field.
If you need to specify 2 strings (a RW and a RO), then you would be manually editing the element (via the UI or dci) and setting the strings accordingly.
Release: LHBASC99000-6.2-eHealth-Live Health Upgrade Elements