II don't know how you can melt anything down in the fitting room unless you tell it to fit an object to something it doesn't match fairly closely, like a shirt to a torso. I regret the loss of the old SM forum, where I covered all this and therefore there was an easy link. Shoes aren't like other clothing items in the fitting room unless they're flats, when you can risk clicking the Fit button for a low number of iterations. You have high heels. Here is what you do. I assume you have have La Femme (LF) in the Pose room. Select her and, just to be sure, on the Figure menu, select Zero Figure. Always start with a zeroed figure, though we are going to un-zero her feet.

Add your shoes, and an obj is fine to start with. Drop them to the ground, again just to make sure. Pose LF's feet to to fit your shoes, which will require you to raise her on the y axis. Do NOT move her on the x or z axes. When everything looks good, save your work

Go to the fitting room. Start a new session. Select your shoes as the object, and don't zero them. Select LF as the goal, and do not zero her. She will appear on her tippy toes with the shoes aligned. I always change the pulldown menu from Tighten to Rigid Features so you can double check visually that everything lines up properly. Click Create Figure and name it. Make sure that transfer morphs is deselected and auto group is selected. Deselect all the rigging by clicking the topmost box. Select the rigging for the left and right legs down to the foot (NOT the metatarsal or toes). This will create a figure that you can pose, e.g. bending the ankle. Save your work.

Go back to the Pose room. There is your new figure, the obj, and LF. Select the obj, and on the parameters tab, make it invisible. Select LF. Zero her. Now, pose the shoes to fit her zeroed feet. The toes of your shoes will be pointing up into the air, but shoes like yours have a rigid sole. The toes don't need to be rigged because it doesn't bend. The heel will be pointing down and forward at a roughly 45 degree angle below the plane of the ground. Save your work

Back to the fitting room. Start a new session. Select your new figure as the object and do not zero it. Select LF as the goal and DO zero her. Create Figure, name it, and again make sure that transfer morphs is deselected and auto group is selected. Same deal on the checking the boxes ONLY for the rigging down to the foot on both legs. Let her rip. Save your work.

Back to the Pose room. Conform your new rigged shoes to LF. Pose LF's foot and toes to match one shoe, drop LF to the ground. You may have to move LF up on the y-axis to align the bottom with the ground, but you'll have to do that every time anyway. It's just nice to see and looks better when Poser creates an icon. Then use Pose Symmetry on the Figure menu to copy that to the other leg. Save this pose to your pose library. I have a folder of poses for each figure (e.g., LF, Dawn, etc) for each set of non-flat shoes, Click the +, name the pose, and click select subset. Deselect all the rigging, then check the foot, metatarsal, and toes for both legs. Then OK, save.

Now add your shoes to the Character library. Create a folder, select the shoes, click the +, etc. It may be a Mac thing, but I always have to do that twice with something I've just rigged in the fitting room before it saves properly.

I hope that helps.