Things are obviously tight in FW. I had two aircraft trying to submit IFR flight plans to me between Mildura and Moorabbin last week. I said no because I was too busy, call FW. FW told them they were too busy call ATC. They seemed incredulous they couldn't get a plan in, but I had other stuff to do; don't know what FW's excuse was, or why they couldn't do it on the phone before they left.
Things calmed down a bit within 20 minutes so I told them to go ahead. FW were still 'busy'.
Talking as a pilot though, if 'on-request' or 'lower priority' or 'add-on' services like radar traffic on VFR to IFR are always available, even during peak periods, then the customers are being overserviced, so it is GOOD if such is not available from time to time
