Claude, you can use the 2nd option to create one tab on each line, but it's really intended to creating multiple tabs, one at every interval.
If you really just want a single tab per line, then disable the 2nd option, and enable the first option and that will ensure you get one tab per line that falls within the parameters.
For the kinds of things I am doing (fairly small) I find that one tab per line is plenty. I included the second option for those cases when I have long parts and want more than one tab per long line.
A possible third option might be to say "for lines longer than N units, place X tabs on each line" (evenly spaced). That might be useful in some circumstances, although option 2 probably will work just fine.
With a part like this one, I would still use double sided tape to hold the piece down and then the tabs will help prevent twisting.
It would be great to put a tab or two on the curved profile, but I have not found a way to make it work. I've written the algorithm, but don't have enough data available.
Steve