Both the transmit and receive radios must have this feature turned on for proper operations. If either is turned off, then there will be poor audio clarity, which can be construed as a range issue. At maximum volume, LLE can degrade the intelligibility. This kind of problem usually exists in high noise environments. Again, intelligibility can also be construed as range issues.
Compression is also another type of filter for audio.
It is a feature to be used within the HT Professional series radios. The audio level will drop slightly also. When used with other types of radios, the audio quality will also be affected. All of these side effects of the compression feature can be construed as a range issue. Auto power mode will automatically adjust the power accordingly to the RSSI level received on the last transmission.