That is for the 500 frames in the test animation.  During the setup first 60 frames it was about 3-4 seconds per frame. But when it got to moving that jumped to 10-12 seconds and I saw a couple that clocked in at 18 seconds.  But the set-up part is easy as nothing was moving except the dress.  how many frames did you use?  Standard 30?  If so a 7-minute simulation works out to about 14 seconds per frame.

And as I have said above My work on the tiers was only a single set of vertexes painted to a specific weight as part of a larger testing experiment.  There are two weight maps on each tier along with the single vertex line.  Since weight maps can be added together I have the whole tier weighted at a value of .0200 and that is super simple to do as you restrict the weight painting to a material group as in this case Flying X.  Then you set the constraint dial to a value that gives the droop you want.  For the 3 tiers that ranges between .38 and .45 depending on how heavy the tier is.  And each tier does have its own set of maps, not necessary as you can put that all in the same group, but I like to have control over how it looks.  Then I put in the single line of weights on each tier and their value was .05 and they tied into a single constraint dial.  When a constraint dial is set to Zero then that weight map has no effect and you get the look of the first picture I posted above.  Then I just changed the value of the single dial and you can see the effect as the dress parts with that weight start to rise.  And as I said if I went in and painted the single line with a wider brush that has fall off instead of the solid Black brush with a fixed value assigned then the dress parts would rise the most in the center and curve off on the sides.  Which would look a lot more like what you posted.  My point of the pictures was to show how much control you can have or the end user as the dials are part of the dress dials, and you don't need to be in the creator mode of the Poser Cloth room to make those changes.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13, 14