If a pipe is placed underwater, it renders as if a full block is taking up the space and looks rather out of place.

Buildcraft won't be using AquaTweaks. Recreate this issue in BuildCraft/BuildcraftCompat.

Quick question, though, should rendering fixes have to be part of a separate mod?

Alright, recreated it there.

@larrythemodder it is not render fix. It is standard behaviour of MC that non solid blocks look different under water. BC has policy that it should not depend on other mods nor link them. This is why BC Compat was created. You should usually have it installed either way.

To my best knowledge, AquaTweaks makes patches into Minecraft itaelf via coremods to provide the functionality. I am not going to have coremods within BC, if only to let myself sleep at night.

@Kubuxu Alright, makes sense. Thanks for clarifying.