A little over 2 hrs for these last two I did. They are only 16" X 7.5" and I adjusted my depth of cuts to speed things up. I noticed that I can get the same effect with shallower cuts as I did with deeper cuts. I’ve tried 2 stage carving and whenever I do, I get a lot of tool mark and random defects (my Z is good, my system is square, spoil board flat). Things just don’t line back up even though I use the 3 axis touch plate. With the 1/16" bit, I have minimal sanding to do and it only takes about an extra 30 or 40 mins to carve.
I have some more of these to make, so I will try the 2 stage method again on some scrap wood first.