That's very insightful Jen !I did a small flat project fairly recently. It's not the scope you're talking about, but the principles still apply. If you pour directly onto the floor, you should probably have a thin coat of mold release under your pour. Some people use cooking spray for small molds. I don't know why it wouldn't work for larger areas. It has been suggested that any residual oil should be washed off after. I don't know whether it would have a negative effect on the latex, but best not to risk it, I guess.
Also, when you peel your finished product up, it can stick to itself and be difficult to re-smooth. A little dusting of cornstarch, baby powder, or similar helps keep that from happening.
Maybe you've already considered and dismissed the idea, but I'll bring it up anyway. Sheet latex might be cheaper, and you can get it in various thicknesses and a wide variety of colors. It's what I'm working with for bat & gargoyle wings. You could texture it or build it up in spots with liquid latex (if you prep it for adhesion).
I've never heard of sheet latex....
Expound....What is sheet latex?
Don't say you don't give a sheet !
What size's does it come in? And where might we acquire some?