Version 8.2 already supports multiple databases on the same connection/server. Officially only MSSQL. Two databases using a different driver is only possible thru RDS.

Using DFConnId.ini is not possible as mandatory information to build the connection string is missing. DFConnId works with the DataFlex CLI Connectivity Kits only. Can't you get information out of DFConnId and use this to alter your connection string? Of course you can do that.