If TWOK followed TOS's use of dilithium crystals, then it would make sense that room is part of the "Main" energizer. TOS, unlike in TNG and later, used the crystals as part of the energizers and was separate from the M/AM reaction.
I suspect that podium Spock accessed is similar in function to the machinery in the middle of the engine room floor that showed up in Season 2 of TOS. And like TOS which did not start out with the machinery in the middle of the floor in Season 1 and moved there in Season 2, then TMP and TWOK could mirror S1 and S2 in terms of engine room modifications.
The big difference between TOS and the movies is that the newer engine design probably is more dangerous but gives more power, IMHO.