Maybe. It probably depends on a number of factors. Those bags don't look much (any?) wider than a water bottle and most of us are used to having water bottles in the main triangle. In general I think they are pretty skinny. REI lists the medium size Tangle bag as 19.5 x 4.75 x 2.75 inches. Pretty sure the 2.75" is the width. It doesn't seem likely to be a big problem. Also I suspect even if it initially gets in the way a little it might be something that we can adjust to.

I have't used them either though, so just guessing. I know that I tend to be fairly tolerant about stuff and think I'd get used to it if it was iniitially an issue. Could be wrong though.