Could we assume that much of the internal partitioning of the ship / engineering section has been removed for some reason (to reduce mass for spore drive experiments ?) and that those turbolift rails would normally wind their way between floors, bulkheads, rooms etc. ?
Or then there were no internal partitions to begin with. Fanfic has traditionally had these triangle-hulled ships as shuttlecarriers, with plenty of unobstructed interior room in these exceptionally shaped secondary hulls. Perhaps Starfleet took one of those and crammed it full of harebrained experiments in its quest to win Burnham's War? Since only the Spore Drive ever panned out, the other experiments were eventually removed, leaving the ship with most of her original interior caverns, only now filled with infra originally designed to accommodate stuff that no longer is there...
Timo Saloniemi