I see that you've already tried Meshmixer and didn't find it helpful, but I wanted to call out an article and accompanying video that I recently found which helped me understand Meshmixer's support generation feature a bit better. It isn't magic, but it is pretty flexible and you can customize them. Plus, you can export them either as a separate file (to be imported via Slic3r's Load Part for example), or as part of the primary object STL file (though you loose the ability to set different print settings for the supports). Much of my printer's time is also devoted to 28mm figurines and I've had varied success with them. There are some models whose detail is too fine and which require too much support to be worth it considering the cleanup - I have a bucket-of-shame that's full of them. I just ordered an upgrade for my printer to allow me to print with multiple filament and I'll be seeing if soluble support material is helpful for those small details. Barring that, I've found that some prints do better with Meshmixer's supports while others do better with simplify3d supports, while others still do better with slic3r supports.

Summarizing the article on custom Meshmixer supports:

1. Open your model in Meshmixer


2. From the top menu select View – Show Printer Bed


3. Select Edit – Transform and move the model to the middle of the print bed
   
   
   
   
   • This step is important because Meshmixer won’t generate any supports outside of the print area
   
   


4. If you want to print the model on a different scale, scale the model now, again by using the Edit – Transform. It’s better to scale
   the model now, because an additional change of scale later in slicer
   would also affect the generated supports, resulting in either too thin
   and weak supports or too thick and hard to remove supports.
   
   
   
   
   • Change the Scale X (Scale Y and Scale Z) to the desired value (1 = 100%, 1.5 = 150% etc.)
   
   


5. Select Analysis – Overhangs
   
   
   
   
   • You can now adjust the Angle Thresh and see a live preview of areas of the model that should be supported
   
   


6. Click on Generate Support to see a preview of the support structure
   
   
   
   
   • Every time you make changes to the support settings you’ll have to click on Remove Support and Generate Support to refresh the view
   
   

(The video in the article goes into greater detail on the settings available in step 6.)

7. Adding and removing supports manually
   
   
   
   
   • You can create a new support by left-clicking and dragging from an overhang to the ground or from an existing support to the ground
   
   
   • Hold down the Shift key to ignore intersections of the support strut or any other warning and force Meshmixer to generate the new
     support (use wisely)
   
   
   • You can also click on an existing support to generate a new strut going down to the build plate
   
   
   • CTRL + Left click on an existing support to remove it
   
   


8. When you’re happy with the support structure you can export the model and the support structure together as STL by simply clicking
   Done and clicking on the Export button in the left menu


9. Alternatively, you can select Convert to Solid to create a separate mesh from the support structure. This will let you set different
   settings in Slic3r for the supports and for the model itself
   
   
   
   
   1. After choosing Convert to Solid choose Edit – Separate shells
   
   
   2. Export both the model and the supports as individual STL files
   
   
   3. In Slic3r first load the STL with the model
   
   
   4. Double-click on the model and choose Load part…, select the supports STL file
   
   
   5. When the STL loads, you can overwrite some of the settings by clicking on the green plus icon