[Therion] Line steps -attr c 4

I'm having to draw some walkway grills and a couple of flights of stairs and have just found the -aatr c (number) option to be used with line steps to create any number of stair treads you desire. Fantastic I thought but the command only seems to work if there are even numbers of line points in the polygon. If you have an odd number of points then your polygon is rendered as a red outline, which to be honest I think could potentially be quite useful for strange man made features. I like this so I thought I'd share. https://therion.speleo.sk/wiki/drawingchecklist details under Man made structures. Nick