Can’t say as I agreed with your assessment ! The mods- as described - would have made the aircraft “less, rather than more” responsive to pilot input in the roll axis IMO. IAC, Its not evident what role - if any - the mods had in the accident at this time. The loss of the elevator trim tab I’d see as even less of a “problem” as I’ll bet a lot the aircraft was weight balanced to minimize “trim drag” in race configuration.
That said, its all - including my conclusions/suppositions - is “up for grabs”, at this point !
A real “plus” for the NTSB is they had personnel on site ! Its also rumored there’s on-board video chips and telemetry that may have survived the crash.
I think it imperitive we all remember this the first NAR incident - in over 45 years - involving spectators ! All - any - of us attending any sort of racing event assume some element of risk ! Its printed on the ticket stub ! >PS
My guess is the FAA will declare the Reno air races too dangerous to continue and I happen to agree with that.
If a sport is so dangerous as to be regularly fatal to competitors and/or spectators, it should not be sanctioned.
Fatality of pilots in wartime is a necessary risk and result. The death of pilots as a consequence of "sport" is akin to gladiator barbarism.