Yeah then read the first line of my previous comment, it explains how to make it possible to make it load from bottom.
The old BC Sidedness (aka: fuel from bottom) does no longer exist in ANY Mod, since Hoppers of vanilla MC are a thing. Hoppers dont work without gravity so the bottom Side of most Modded Machines is no longer an Input at all.
And IC2Exp just accepts from any side by now afaik.
Also the IC2 Wiki does NOT apply to IC2C, it doesn't even apply to IC2Exp as it's outdated as fuck.
"The Sidedness of IC2C is different, try inserting an Automation Upgrade using the Tool that looks a bit like but with a wrench below it."
a regular generator doesn't have anywhere to add an automation upgrade...is why I don't think you understand my issue.
the vanilla hopper connection is probably the root of the change, I understand why it changed now. But it should be possible to make any side in or out.
Complex arrays of machines are more flexible when they can be arranged according to the desired function and not cobbled with a bunch of extra piping to satisfy an inflexible design.