I fully understand Input overvoltage protection for the amplifier (page 16).
Let us AD8610 , PS +- 16V, on + input serial protective resitor 100k.
What maximum non destrucitve voltage on +input AD8610?
AD8610 is only specified to operate in a maximum supply voltage of ±13V. Above that, the part will be damaged. If you need ADI part with more than ±13V supply, then you may use ADA4627-1/ADA4637-1 which can go as high as ±18V.
As to the input overvoltage protection of AD8610, I'll get back to you on that.