The Charging Party may request a Sustantial Weight Review

one more, maybe?

The Charging Party may request a Sustantial Weight Review

La parte querellante podrá solicitar una revisión de fondo.

:)

Another option:

La parte querellante podrá solicitar una revisión en cuanto al fondo del asunto.

:)

thanks for your suggestions, I'll play with them at put them to use. Thanks for taking the time to respond!

We're here for that, Zorro!

:)