LT3761 LED driver explodes
That must be very frustrating.  

I don't see any test results especially those that should be non-destructive attempts to characterize sections of the design.

Can you test the Boost FET path alone  by injecting external voltage pulse at equiv Rs?  The path in red is the current path of destruction. (pun intended)    

I believe when Rs fuses open, then the IC fails 2nd with OV then avalanche failure.  The avalanche diode may not be fast enough for recovery time. (?) Then the FET overheats.  So FET specs and all other related datasheets are important to include in question..

The Gate pulse and current pulse sense ought to reveal your problem from resistance and Q charge effects.  High quality measurement methods need to be done with calibrated spring probes. ( meaning flat mV traces on ground signal with current pulses flowing under it.)