Which VTF Scale are you using?

The digital scales can be off.

I keep a new U.S nickel in my digital gauge pouch
it weighs 5 grams for times I want to calibrate.

I think he’s referring to this one? Looks pretty good for that price!

https://smile.amazon.com/gp/product/B08H5DBZTK/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

That one DOES indeed resemble the Ortofon DS3, except for the weigh pan shape.  It's a good candidate for you, if you want an upgrade from the Riverstone. I can't believe how cheap those Chinese-made digital scales (see my URL above) have become since I bought my version of one. 

I use a cheap ($15) scale I bought for measuring cure for meats. It's accurate to 0.01g (well, probably 0.02). Conveniently, when I set it on my plinth, the top is the same height as my platter.

So apparently the apparent weight of meat is not accurate, when the weigh pan is not at the level of the LP surface.  Interesting.