For some reason (and it may be I'm just bad at create) I have 2 deployers side-by-side on a rotational contraption with a filter for dark oak saplings, when stationary, they're holding the saplings, however, once it starts moving, they don't place the saplings and I can't see it in their hand. Is this issue solved in b or c?

it is possible this is due to chunk claiming systems preventing the deployers from working. This needs some more information.

Alright, what more information do you need from me?

They probably want a modlist and screenshots of the contraption.
Also, have you tried allying "Deployer" in The FTBChunks Ally screen (if installed).

mod list

Contraption
The desployers seem to work while stationary but when it begins to move they stop working, even when I'm right next to the machine. Again, I might just be bad at the mod, but it makes creating an auto tree farm really hard

your deployers are too low, move 'em one block up

(;-;)