Thankfully, it appears that I was wrong. It definitely seems that UHF 2 (453.750) is a permanent ISPERN patch after all. There were a few days not too long ago were the patch was de-activated, but was back up not too long afterwards. I recently listened to a pursuit initiated by Riverdale PD, and they were transmitting on UHF 2 instead of ISPERN. After an ISP dispatcher stated that the unit was "not on ISPERN", the frustrated RPD officer later said that UHF 2 as labeled as "ISPERN" in their radios.