I've not used all of these lenses, but most Leica lenses are pretty sharp close in, especially if you stop down a stop or two. The obvious two that *aren't* sharp are the 35 and 50 Summiluxes, non-ASPH.
I don't find the 50 Summilux ASPH too sharp for portraits. Even though it does have a floating lens for close in corrections, I've heard the 50 Summicron and 50 Elmar are still sharper at minimum focus distance, though maybe by an unnoticeable amount.
The 90 macro should certainly be optimized for minimum focus.