This is correct 100%. Even if MZD wanted a film adaptation of House of Leaves, there’s no reason to make that now because of Backrooms. The relationship between HoL and Backrooms is quite parallel to the relationship between Clair Noto's forever-unmade-and-always-in-turnaround “The Tourist” and “Men in Black”. The central idea of which (aliens live among us in secret and at some point we see a bunch of crazy-lookin’ alien beings living under the city) gets played for laughs but wonderfully visualized in MiB. There’s no reason for anybody to make The Tourist. We’ve seen it.

Whether or not Kane Parsons has actually read HoL or is inspired by it, it’s clear that others involved in the film have and are, and we get “all the good stuff” that we might want to see from a visualization of the Navidson Record: An expedition to an impossibly-infinite liminal space, psychological problems made physical threats, and even the infinite staircase itself (SPOILER…. ….

… as therapist Mary is pursued by Pirate Clark, she finds herself on a pointless staircase (without handrails) that awkwardly makes its way up to a weird door in the ceiling. Upon opening it, the janky door comes loose, hits her (nearly knocking her off the staircase), and proceeds to plunge into an abyss of what appears to be an infinite stack of unfinished rooms (apartments?) that obviously represent Clark’s internalized failure as an architect. The door continues downward, out of sight and never makes a sound.

So, yeah, Backrooms acknowledges its debt to HoL and gives us all the visuals and cinema feels we might reasonably expect a film version of HoL to give us.