There are lots of reasons to choose a competent independent. The nomenclature describes the reason. He is independent. This means all techniques are accessible including factory approved methods.
This independence allows all sorts of repair techniques not suggested by the manufacturer, including used parts, non OE parts, improved parts (parts redesigned for handling, horsepower, longevity, etc). It includes repair techniques including A/C hose repair (here again the independent can improve on the part by rebuilding hoses with barrier hose where new would be the same old R12 junk), TIG welding, machining, electronics soldering and repairs.
Generally rebuilding of any nature has been discouraged at the dealer level. If one chooses the dealer level of repair the point of obsolecence is reached at a much younger age. Obsolecence being the point where repair costs make new purchases economical. Sort of in their best interest not to lengthen that time span.
Bosch Master, ASE Master, L1
33 years MB technician