I don't root in SM, I root in the bag with a paper towel. Once "significant" rootlets are showing in the bag, I put into a perlite-heavy mix (I think I'm at 20% Fafard 3B / 80% perlite at this point), I let them get rootbound, then transfer the rooted mass into a larger pot. It's been working out really well. With other fruit trees and plants in the past, I've used a more potting-mix-heavy ratio for potting, figs seem to like more porous material to get started in. I openly admit that I've never rooted this many fruit trees at once in my life, so I learned a lot through my trials and sharing with a couple other fig-rooting-newbies who were exceptional enough to collaborate with me.
With the four cuttings I talk about in this thread, I deviated from that after some inspiration from a post at GW forums, where someone (don't remember who at this point) mentioned using 50/50 Turface MVP/Sphagnum moss in rooting cups. The result for me with this new cupping medium was profoundly different from my normal one. The ability to consistently control moisture with the 50/50 Turface/Sphagnum mix was next to impossible. It would hold moisture in the middle (at the center only) for far too long, with no moisture to the outsides of the cup. So, the risk of overwatering was huge, and the only way to work around it was using large needle used for injecting liquids into meats prior to cooking. This was cumbersome and too time-intensive.
I was kindly given a cutting of JH Adriatic this year from a fellow fig friend. I indeed tried your suggestion of going straight from bag (or moss) to the pot, using one of the blue pots pictured in my last post. It appears to be working out OK? I can't see what's going on below the soil, and it takes up so much room in my bin that I'm reluctant to try this method again. I see the inherent risk of transplanting from cup->pot on a young cutting, but the having the ability to control or influence a cutting based on what rooting you're seeing is well worth it in my opinion. I wouldn't have it any other way.
I'm tempted to try Jon's 'new baggie method" next year, just to save room and give that a shot.