Of course I didn't quote PingBirdPong but Tony's Table Tennis. Why are you stating the obvious?
I also believe PingBirdPong knows what the situation...
If inner has more arc that means easier to overshoot the table, it is worse for blocking and for flat hits.
That is not personal experience but just...
If softer rubbers don't generate less spin then do they generate more spin or same spin as harder rubbers assuming it's the same player that's using...