I can't see it being a clothing layers or complexity problem - Toht, Henry Snr, both really just men in suits and countless companies have done this without great problems recently (Medicom actually with Henry himself). Mola Ram's costume was basically a long strip of fabric, black on one side and red on the other - sure that might take a little to work out exactly how to dress him, but once you know it should just be a matter of adding some snaps and the assembly should take care of itself - the thickness of the fabric I can't see as an issue either - Hot Toys were able to make a fully lined cape for their Batman and it wasn't too thick. If it was the Grail Knight we were waiting on, then sure, maybe the costume had something to do with it, but there are plenty of characters where the existing costume "technology" should be more than good enough to produce them. And if Sideshow aren't as advanced as Hot Toys or Medicom in the fabrics department, well again they have no one to blame but themselves.
I apologize if I only ever seem to criticize Sideshow, but the Indy line is/will be the first thing that I have bought from them, so I don't have the depth of experience that a lot of you guys do where you've experienced a good line. Instead I saw a great head sculpt and got excited, saw the paint job drastically reduce the likeness, have had the release date delayed on me, and been given no other chances to send them my money for other figures (they probably could have got me to buy visually uninteresting Belloq if they'd only announced it earlier before I was convinced the line was dead in the water). Contrast that with Hot Toys, and in the space of about two months I've ordered five of their figures (four of them from the same property) and received two already. I guess I can thank Sideshow for getting me interested in sixth scale stuff, but I doubt they'll keep me as a customer beyond this one Indy figure - I have zero interest in any of the other lines they carry, except for some that are produced by other companies and just distributed by SS. It's likely even that I will cancel Indy when I see the production paint job. I don't want to be waiting for another six months for my figure because I had to send it off to someone to paint it in a way that the likeness is true to Harrison Ford.
Rant over - I now return you to your regularly scheduled program.