I use a table but, I draw in in a canvas to control the position of the flowables, this because I have a template in a pdf, an I merge with pyPDF.
The wrap is done i
I know that Postscript's reference is the lower, left corner. I'm guessing that PDF is the same, so you subtract from the y value to go down. Print the beginning and ending "y" values in the function to see how they are changing and adjust the "y" value depending on the length of the sentence. And how does the function know what "height" is? I use ReportLab but could probably help with a specific example if you care to post one.