Of course, there are different ways of doing it - and a lot of places will just work directly from a 'stock template' (including you sending them your ECU), which may work just fine.
Mine was done on a rolling road (before & after) and I watched the guy tweak my map on his laptop as he recommended parameters, but adjusted it as he asked for my input. He then uploaded the new map to my car and we checked her out on the rolling road again. The whole exercise took an hour. He has done 100's of these, each one bespoke - he knows the Alfa engines inside out.
As well as customers having it 'just how they want it', there are small mechanical differences between engines as they come off the production line, also they will wear differently so that when you go for a map, your engine will be different from the next guy's - this is evidenced by the wide variation in power and torque outputs from ostensibly the same engines when they first go on the rolling road. I've been to 2 'remap days' and seen this for myself.
That is why a bespoke remap is a better way of giving you what you want.