Why would a dyno tell you if the engine is in good health? Can it show if parts are prone to fail?
I've heard that remaps can/do get reset during abarth servicing, I quite like the idea of the tuning boxes especially as you can change to different settings as you like.
A dyno won't tell you that you are about to have a major component failure, but it can give you a good idea as to certain problems.
For example if you have a major boost leak, this will usually be relatively obvious during dyno testing.
Generally speaking, it depends strongly from car to car. If you have a vehicle with relatively low miles and it has been looked after then you can usually be fairly confident that it isn't broken. In this circumstance, whilst a dyno test is nice to have, it isn't as neccesary.
Conversely if you have a car with high miles, unknown history and looks like it hasn't been given a lot of love by previous owners then it is worthwhile getting it checked over before tuning.
Of the occasional problems we find with customers vehicles, most of them we discover long before it gets anywhere near the dyno.