Re TSR.2: without delving into various tomes to be absolutely certain, IIRC the resonance on the first flight was due to the early ‘not really cleared for flight’ development engines, nothing to do with the airframe, and was expected. What wasn’t expected was that the frequency would be exactly right – or wrong – so Bee Beamont couldn’t see.
The undercarriage problems, I think, were due to the 180° rotation required and took some solving but aircraft after XR219 had an extra link. As they never flew, who knows…

From memory & being in the middle of the book the sequencing problem seemed to have been sorted quite easily, but the vibration on touchdown was 90% cured by changing the angle of the fore/aft beam so that the front wheels touched down just ahead of the rears & thats what the link was doing. A rigid one was tried & there was then a telescopic one designed & fitted but not flown. Seems gyroscopic reaction of wheel spinup was the cause. Also mentioned once but not referred to again as being a possible cause, was that the steel material for the prototypes legs were not as specified because of lack of availability, so possibly more flexible?
Keith