Most people, unless they have been server admins, do not see a value in reducing computational resources in their builds, so that can't be the value-add.
Proof of this, Netherrack in Magma Crucibles. KL put it in as a way to get relatively free energy from the Nether without the associated lag that pumping requires. When it was 4kMj/bucket there were two camps.
1: The people who saw it as too expensive since they can just pump lava for free.
2: The people who saw it as too cheap because it didn't require you to set up something as complex as pumping lava.
The fact that it lowered lag on a server never really entered the discussion. Although because of his explanation of why it was done I scrapped plans to ever pump lava and have done 2 Netherrack -> Lava -> Magmatic builds as my backup, on-demand power structure to augment my boilers. Both were in my SSP worlds.
In the end the discussion of balance and cost is moot. Notice that every post pointing out how any proposed balance point is trivial starts off with, essentially, "With this other mod you can just..." Why does it make it moot? Because not everyone plays with that other mod. People add, or remove, mods to suit their tastes. So for every person shooting down balance points based on the fact that "with EE3 you can just do this" there's probably just as many people who aren't using EE3. Balance presuming EE3 is present and you screw over those people. Balance presuming EE3 isn't present and the balance is trivial with it in place.
Note, EE3 is just used as an example, balancing against the synergies of other mods will always net the same paradox.
BTW, KL, if you read this, thank you for these! Saves me from having to try to noodle out how the current incarnation of teleport pipes works!