Ideas for temporary floor fix near tub?

Am handyman half the year usually, but this year's project is trying to revive the ol' family homestead after being a barely monitored rental for nearly the past decade. (It needs everything. EVERYTHING. Like, if it weren't the family home it would undoubtedly be cheaper to buy something else even though I only need to hire out for like, two things.)

In this particular instance, I am looking to make the current bathroom less egregiously unpleasant until I add another compact full bath in the sorta master suite we got going on, and then this one will be completely gutted to the joists to be rebuilt.

At the moment, I just want this floor outside the tub surround to be less squishy and ugly and stop water from getting to the joists. I'm thinking that I'll shove some self-leveling compound in there, trowel it to slope slightly away from the tub surround, glue this layer of torn up linoleum back down, caulk it, and then (sinfully) just glue another layer of slightly less hideous lino over the horrifically poorly over-caulked existing floor cover. Am prolly' gonna lose a fair bit of compound to/through the subfloor (though there might be 2 layers...) but meh, a 25lb bag should cover 6-7sqft at 1/2" and this is at most a 5sqft area at if not significantly less at less depth.

Just wanted to make sure someone else didn't have a clever idea that isn't "doing it right" because doing it right is demolishing the room and I'm not doing that until I either have another bathroom or it's warm enough for me to poop outside lol

Just to get ahead of it:
-Structure is fine. These 2x8 joists are in good condition except that someone cut a 12" section out of one at some point for some reason I can't figure out???? No baths until I sister that up good, but even if this tub didn't skeez me out I don't like baths anyway and the other joists are fine.
-Mold IS an issue for sure (found a dang mushroom under the house,) working on a plan but have to fix front yard drainage first. (Regrade then install french drain wraparound with gutter drain above; crawlspace gets some water features in the rain right now. Pond under the original house, AND a moat under the Eastern addition!)
-I know that most self leveling compound isn't meant for unsealed OSB/Ply but this is a temporary fix, a few months at most. I could also just try to seal it and leave it, but eh, figure a temp fix is going to cost me ~$50 more than that and seal/feel a lot better for those few months.

Let me know if you got any questions or suggestions even if not about this particular thing, I've been taking plenty of video and pictures as I find things and ask myself "what in tarfuckingnation" while exploring this house and feeling validated in thinking we were scraping by lol