Oh, nothing about my method is fast. But I don't have deadlines lol.
I've actually made progress with realflow (by messing with viscosity/cohesion and tinkering with the "mesher") and can say it's viable, but yes, I'm still struggling with textures. Definitely not limited by cinema4d, it's just me. I suck at textures.
I plan on exporting my daz characters + clothes out of daz and into cinema4d. Then completely re-rig them, which will take days, but after that I'll work entirely inside c4d. I believe this will be muuuch faster, at least for me.
None of this is actually holding me back, I'm still stuck designing the game itself. Can't decide on a theme that's compelling enough to hold my limited attention span.