I have a small touchscreen and am using Marlin 2.x. The screen I have is not very responsive and found a stylus works pretty well (https://www.thingiverse.com/thing:4493887/filesl. I downloaded the stylus then made a mount that slides into the rail. For the stylus:

• 100% infill
• Brim on
• Supports
• None- You may want to slow the print down a bit as it can wobble ner the end.
• Some simple sanding post-processing worked well for me.
  For the clip:
• clip needs support but not a lot (I used tree supports) just around the clip part.
• I printed it vertically with a skirt and it worked fine.