While this doesn't disable reverse DNS lookup itself, it does "hide" the hostnames.

1) right-click on the columns in Pingplotter and un-tick the "host name" column.
2) right-click on the very last hop in the trace (the target), click "edit name", and change the name back to the original IP address, this also updates the name of the target in the PingPlotter tab

Gonna leave this here in case someone else wants to see only IP addresses in the trace as well as the target tabs

Case closed I guess