A custom tune means the tuner reviews datalogs, tweaks accordingly, gathers even more data, and repeats the process until completed.
Being on location and on the dyno in real life does NOT mean it's a real tune. Some of the worst tunes I've ever seen have been in person from someone who has no idea what they are doing. You'd be MUCH MUCH better off getting an etune from someone who knows the platform, than from someone who doesn't know the platform but can "tune" it just because they're in person plugging up to you truck.
You will get the same tune whether the tuner is in person or can email you a file online. Yes in person its faster, but it doesn't make it any better. And with the laptop in the wrong hands it can be way worse.
Here's a simple stage 2 truck I did, on 91oct.