I've tried a couple of tablet weave set-ups with designs on the Loomy-Bin Design program. I was curious about how many warp threads I had and how narrow the woven band ended up. Had 10 cards, which meant 40 threads. It was not nearly as wide as a 39 warp thread inkle band. I assume it had to do with there always being two threads on top and two on the bottom for every weft pass.
I also struggled with keeping up the proper sequence of which cards and which directions they were being rotated. I love the designs that are possible, but get frustrated having to un-weave.