Wow, I always thought DCT law was F3 by design requirement. And dual RA is that due to no flare mode, A330/340 included. Slap me if I deserve it, could it be a typo in the manuals?
With regards to F3 then gear-down: I remeber that as well in the past. Later, with a wider undestanding on what were the appropriate instructing philosophies, the company mantra changed - no tricks outside the book were recommended, only smart application of it. Hence for dual RA, unlike in G+Y HYD where the summary advises the swap, standard sequence would be used. But we would deccelerate to F speed before dropping the wheels, goal achieved. Vapp(f3) to F speed difference is insignificant.