Analysis Received Signal at receiver side
Constructive interference just increases the gain of the signal at the receiver, which is designed (using automatic gain control) to adjust the signal level over a very wide range to that desired for reception. So the issue the OP refers to is of no real consequence as long as the received signal is in the (relatively wide) range of the receiver between maximum and minimum signal levels allowed.
Multipath distortion can come in different forms based on how fast the multipath is changing (such as in a mobile environment) resulting in &quot;fast&quot; or &quot;slow&quot; fading, and the relative distance between the paths compared the symbol rate, resulting in &quot;flat&quot; or &quot;frequency selective&quot; fading.  These are the real issues with multipath distortion which are corrected with equalizers in the receiver.
Please see this post which expands on these different fading models:
Rayleigh fading with frequency selective fading channel