The point of Jool and similar tools (there is also one called Tayga that runs in userspace, if you want) is to translate network traffic between multiple hosts, where some only have IPv6 and others only IPv4 addresses.
If your machine has both IPv6 and IPv4 addresses you don't need to any translation.
I interpreted "services with only IPv6 addresses" as IPv6-only servers, in which case some sort of translation is needed, but if these are just processes in a dual stack server, then yes.
If your machine has both IPv6 and IPv4 addresses you don't need to any translation.