The joint mission BepiColombo (ESA/JAXA), currently in cruise to Mercury, hosts the MORE radio science experiment on-board the Mercury Planetary Orbiter (MPO). One of the primary scientific goals of the experiment during the cruise phase is to test the theory of general relativity, by improving the accuracy in the measurement of the gamma and beta of the parametrized post-Newtonian formalism achieved by Cassini in 2002. Meeting MORE scientific objectives requires the use of accurate and stable tracking data (Doppler and range) in three different simultaneous two-way radio links (X/X, X/Ka, Ka/Ka), placing stringent requirements on the spacecraft, ground station and propagation media calibrations. In order to meet such needs, ESA DSA3 station in Malargüe (Argentina) has been upgraded for radio science support over the last years according to a development and deployment roadmap and has played a pivotal role in the radio science campaigns performed to date (five superior solar conjunctions have been supported so far). Unprecedented valuable results have been obtained so far, and further results are expected as part of the remaining campaigns, which will extend until the end of 2025. The use of various novel techniques, the operation of the Ka-band links and the stringent requirements in terms of accuracy and stability have made radio science related operations particularly challenging. This article describes the context of the experiment, the experience gained during preparatory in-flight testing, and the support given to the first radio science campaigns (77 operational passes) from DSA3. Main critical aspects (in particular related to the operation of Ka-links) are described, as well as the lessons learned for future radio science supports (BepiColombo and JUICE missions).