The game I have seen shot with failsafes all died rather quickly, and without a lot of fuss. With no flame intended, instances where game is hit but not recovered often points to poor bullet placement as opposed to bullet performance, except perhaps with catastrophic bullet failure as occasionally seen with varmit bullets.
Instances where game is hit well and travels some distance before expiring may be a matter of animal physiology, as opposed to bullet performance. It has been my observation that a lung shot deer may travel 20-40 yards regardless of the bullet used (or cartridge for that matter). For example, the last deer I shot with a 6mm 95 grain ballistic tip went a similar distance to the one I shot this fall with a X bullet in a .45-70 - both broadside mid lung hits.
Shed petals off an X type or failsafe bullet do not overly concern me provided the shank remaining is long enough to continue to traveling in a straight line for deep penetration. These shed petals may often cause large amounts of internal damage. If you have ever weighed a recovered nosler partition, you will find they often lose 30% or so of their bullet mass, and you will rarely find anyone complaining about their performance on game.
The size of hole on the offside skin does not really concern me either. For one, if the bullet actually exits, it means there has been adequate penetration, and secondly I have notices that deer skin is quite stretchy, so a small appearing hole may not actually be as small as it first appears.