For coding
My favourite one is the VCDS (made by Ross-Tech). It's very well supported (even on this Forum).
Also OBDeleven has the capability for coding changes - as long as you know what you need = it's not been very well supported by the manufacturer.
For vehicle diagnosis
The VCDS is the superior one for interpreting fault codes, for capturing live data, for running controller built-in tests, etc.
A good investment for future fault finding as our vans get older and crampier. Highly recommended

Well, VCDS needs Windows laptop - as the VCDS is Windows only software. However the laptop doesn't need to be a powerful one.
In principle OBDeleven has the same capabilities but the way the features are implemented is not satisfactory.
There are quite a few examples of VCDS diagnostic capabilities around the Forum.
www.t6forum.com
The BCM coding capabilities/possibilities for T6 are summarised in downloads
T6 BCM secrets explored (2024.01 edition)