The lite isn't more accurate; it's just smaller and made more affordable by offering less features compared to the original model.
quote from article:
For 2017, RCBS is introducing the
Chargemaster Lite, meant to be a lower cost alternative to the much more expensive Chargemaster line currently gracing the reloading bench in my shop. The Lite takes all the great features of the regular Chargemaster, fixes the dispensing pipe, and uses a less expensive load cell along with a much cleaner interface to bring a true value based automated powder trickler to market.
For those worried about that load cell comment, fear not. RCBS’s product manager reassures me that the load cell in my legacy Chargemaster is accurate +/- .1 gr from 3-700 grains which requires a very precise, and therefore very expensive, load cell. The Lite version moves to a load cell that is accurate to +/- .1 gr from 3-300 grains. This, along with some other changes, reduces MSRP by ~$200 to $299.95. Given that real world cost on the regular Chargemaster is about 55% of MSRP, my hope was that the Lite would hit the market at a price substantially lower than $200, but it appears from a cursory search of the internet that you’ll be able to pick one up in the wild for ~$210.
So it's just a smaller load cell with the same resolution. This means you probably can't weigh other items thatll bust weight or get close to 300 grains.