YUP, your Engineer is realizing that it only possible to slightly attenuate the CELLPHONE to TOWER signals on 704-716 MHz, cuz they're too close to Ch51 top band-edge (698 MHz), which should NOT be attenuated more than say 1 dB. The BEST that can be done with an LTE Filter is to get rid of the TOWER Broadcast signals on 734-746 MHz (and another higher band) in North America:
Severe OTA Interference From New Digital Services Tower
Max Output Level: 118 dBuV
Need to ALSO specify TEST CONDITIONS, such as either per DIN45004 (A or B or C?) Test Procedures or whatever alternative test is used. Typically the reported OUTPUT voltage value is for either TWO EQUAL Strong Signals [or one x dB stronger than the other] while adjusting the input level so that the 3rd Order Intermod Frequency (for example 2F1-F2) is y dB [46 dB or 60 dB are typically used] below the Strongest Output Signal.