The N54 is direct injection. Techron will do exactly nothing for the intake valves, as the fuel and any additives never contact them. In the VW/Audi world, many owners will simply DIY: pull the intake manifold and manually clean the valves. It costs almost nothing, but the time investment is 4-6 hours.
Running high Nitrogen fuels such as Shell V-Power is known to reduce carbon build up, but at some point, all direct injection engines will require valve cleaning.