Yep, that's an error: I overlooked the -5D due to the way some of my reference material was set up and so it only has the availabilty it had on the 3050 chart. I'll be deleting the -5S completely, under the assumption that if there's both Steiner and Davion variants for the same machine, then each House only gets their own variant unless the fluff specifies otherwise. This makes sense I think, and also serves to help differentiate the factions.
As for a few higher-tech machines in lower-tier units, by 3057 some have begun trickling down. It's still not common though, and the little L notation is meant to represent that. The instructions are in the main document, but essentially D and F-rated units have roll modifiers so they can't roll as high, and if a F-rated unit rolls anything with an L (Lostech), then they must reroll. The way the -5D is on the table, it's only possible to be rolled for C-rated units.
I'll update the linked table in a few minutes. Thanks.