The margins for 4:3 and 16:9 slides (minor?)
I noticed that the margins left on the title pages were based off the ratios for 4:3 slides and were not adjusted according to user-specified aspect ratio (say 16:9). This is a minor issue (I suppose?) - but need to check more and perhaps adjust these.
Ref:
\newlength{\tenpxh}
\setlength{\tenpxh}{.0185\paperheight} %10px out off 540px = 1/54\paperheight
\newlength{\tenpxw}
\setlength{\tenpxw}{.013889\paperwidth} %10px out off 720px = 1/72\paperwidth