It’s not possible to configure controller in Kie Server S2I template. Execution Server is mapped into the controller (Business Central) by Kie Server name prefix. So if it's created new Kie Server S2I named default-s2i-execserv then Kie Server tries to connect to controller in service named default-s2i-buscentr, if this service doesn't exist then in Kie Server log we can see warning about not existing connection.

It should be able to choose controller in Kie Server S2I template. Controller can be set by service name or by URL.

Controller can be configured later by updated deployment env. variables. But this isn't friendly option.