Apologies, I have been meaning to answer this one for awhile but was doing a bit of research. Truth be told none of our current platforms have additional filters to protect the 2.4G band from cellular interference. We are considering adding a specialized filter in the future, not so much because it is needed but because it appears that some competitors have convinced customers that it is a problem. I discussed this potential issue with one of our distinguished engineers and his assessment is that the potential for cellular interference is very low in most deployments. Without additional filters, he estimates that there will be no interference if the cellular tower or cellular repeater is more than 40m away from the AP. With different types of filters you can reduce that distance to as low as 1m which is what some competitors claim. But most customers don't have DAS systems or cellular repeaters close to APs. Even if they did, the worst case scenario being described by competitors is based on a DAS antenna pointed directly at the AP which is unlikely. In the worst case scenario, assuming that your AP is within 40m of a cellular repeater, the additional filter would reduce interference with the AP TX/RX but the Wi-Fi clients are unlikely to have any additional protection. At the end of the day, it is more likely that you will have 2.4G interference from microwaves, BLE, video bridges, handsets, etc. than from cellular. So your best defense is to move as many as your clients away from the 2.4G band to Wi-Fi 5G to eliminate the risk altogether.