I've built a small, non-scale excavator based on a Deere 135G. It has a standard Boom and Stick, a custom-designed quick coupler, a large bucket (originally designed by Freizeitopfer on Rebrickable.com, but I had to modify it to fit my Coupler design), and a thumb. I also added a small Backfill Blade, using a mini LA to raise and lower it. I also have a tilt Bucket, narrow trenching Bucket, and a stumping attachment for it. It is a zerotail, I was able to build the Counterweight compact enough to stay within the Tracks when the superstructure is turned 90 degrees to the undercarriage. I didn't design this on LDD or Brinklink Studio, and I also don't know what the piece count is. Its similar in size to the excavator from set number 42175, Volvo FMX Truck with EC230 Electric Excavator. As of the posting of this thread, I was unable to attach a photo of my MOC due to the size being too large. I''ll have to figure out how to do this correctly.
The only non-lego pieces on this are 40 metal washers I've used as Counterweight.