Because of the way this mod stores information and the way create reads it, there are a few incompatibilities between the two

• stockpile switch

• doesn't work on 1x1 drawer.
• works on 2x2 but detects only up to two stacks.
• works on 4x4 but detects only up to 4 stacks

• contraptions

• don't detect drawers as inventories for storage

Creators-of-Create/Create#2239 related issiue in create github

For stockpile switch, it looks like they artificially limit their handling to a normal minecraft stack size. It's valid for IItemHandler imeplementations to report stack sizes much larger than that, and SD does as it's a kind of deep storage mod.

Not sure about the contraptions, but if they're trying to interface with Minecraft-style, this mod is not compatible with that interface. It's only accessible through Forge's IItemHandler.