Hello
Postgresql does not log statement parameters on log_lock_wait. Because this is not implemented: https://github.com/postgres/postgres/blob/REL_10_STABLE/src/backend/storage/lmgr/proc.c#L1461
Compare with errdetail_params routine in this file: https://github.com/postgres/postgres/blob/REL_10_STABLE/src/backend/tcop/postgres.c#L1847
Currently query parameters can be logged only at the end of successful query execution.
regards, Sergei