For Patreon's purposes, this is not enough to not be incest (blood relations don't matter to them). Beyond that, it will generally turn incest AVN fans away. For a lot of people, stepcest is worse than being completely unrelated, because it's completely unnecessary. AVNs aren't mainstream porn videos, which use step-relations to avoid a different kind of censorship, so either they use the "roommate"/"landlady" workaround, they create wholly different patched stories (like My Dorm), or they use itch and SubscribeStar and go full-on with blood-related incest.
If Alaina is an LI, Patreon will eventually slap Laundry down if that relationship is not retconned in the core game and re-implemented via a patch that is never mentioned or distributed on Patreon (at which point there's no reason to keep it a step-relation). While step-relations are acceptable in mainstream porn as a stand-in for incest, there's a reason successful "honest it's not incest" AVNs on Patreon use the "roommate"/"landlady" stuff and an "unofficial, fan-made" patch.
On a different note, like a few others in this thread, I'm personally waiting to hear an answer about future harem or not before I try it out and see if it's worth supporting, now that we've gotten an answer on NTR/swinging/sharing.