Uberdata

I am curious about this. I searched but I have other questions.
#1 - has anyone done this to a gen2 gsr? if so how is it?
#2 - what are the dangers of chipping your ecu this way?
#3 - would it be better to just get a “dummy” or “test” ecu and use that for tuning and run my normal ecu everyday?

any help would be appreciated. thx.

M.