On our tandem, we have been running 53-39-26 in front and 11-40 in back for a few thousand miles. We use a Shimano 10-speed FD and a Shimano RXL M971 RD, now attached to a link. This all works very well. I don't usually shift beyond the 3rd largest cog in back when in the big ring, though it will shift into all cogs. The middle ring works on all cogs. I don't usually shift into smaller cogs than the 5th largest in back. We have a 10-speed Ultegra left brifter and an Ultegra 9-speed right brifter. When the right brifter finally gives up someday, I have a 10-speed in waiting. The RD works fine with 9 or 10 speeds. This has been an excellent setup. I also run 26T grannies on my single triples, thus getting closer spaced gearing for climbing, where it's most needed. I use chain catchers on all my bikes.

IME chain wrap is the least important variable.