There are a lot of videos and posts about modifications to the RCBS chargemasters. They mostly revolve around making the RCBS Chargemaster 1500 combo units faster (programming mods) and drop powder more consistently (straw mod).
Greg over at Primal Rights also has a very nice write-up on these "Digital Scales - Exorcising the Demons" - and covers some ideas like using a UPS with power conditioning to help clean up the power so your units maintain zero better.
I have made a few modifications that I think are pretty unique and solve problems I have had, here they are:
Here in the West, it is particularly dry. This results in a lot of static electricity - particularly with plastic and movement - like gunpowder. This annoyance shows up in powder throws, powder funnels, plastic scale pans - pretty much anything plastic in contact with moving gun powder.
The symptoms show up when moving powder from one container to another, and weighing very small items (ie gun powder) on very precise scales (particularly plastic ones).
One solution commonly advertised is to use dryer sheets - which help reduces static cling - and that is certain one localized solution - the idea being to wipe down plastic housings with the dryer sheet. However my family doesn't use dryer sheets, and I wanted a more permanent solution.
My modification consists of two ideas taken from IT work. A anti-static work mat - which also deadens vibrations - which helps avoid dropping extra kernels. And an anti-static wrist band around the main static generator - the clear plastic powder reservoir. The wrist strap is connected to a common ground point on the mat - which is connected to a household ground. In this case to ground cable which connects to the house copper water pipes. In your case, maybe the center screw on a properly grounded electrical outlet.
This eliminates static for my setup - hopefully it will for yours as well.
I think the entire setup costs around $30 or so.
Using the draft shields on the RCBS Chargemaster 1500 is important. The scales are very sensitive. Your breath, or other drafts (heat and AC) can cause the scales to incorrectly weigh your charges. The downside is that when opening and closing the draft shields you bump the plastic housing on the units which cause extra kernels of powder to drop from the dispenser into your pan. This is pretty annoying. To combat this, but allow the continued use of the draft shields, I just use a rubber band as a bumper. I don't need to completely close the shield, just keep it mostly closed to avoid drafts.
In both my RCBS Chargemaster 1500 units, I use the straw mod. A couple of points I want to make on that mod:
I see no difference between the saw tooth version and the flat cut version in over/under drop or speed - so use which ever you want, I am using both with not differences.
Some sites recommend using a LOT of straw - all the way back to the end of the aluminum tube in the powder reservoir. This will slow down powder dispensing. The reason is simple. The inside of the aluminum tube is threaded. This is to move the powder down the tube and out into the pan. The problem is the threading at the very end of the tube where the powder dispenses into your pan can cause a build-up of kernels which don't drop smoothly, but in a clump. The straw modification fights against that tendency by making the end of the tube smooth, so there is nothing to bunch up the kernels.
However, if you run the straw all the way to the reservoir you lose speed since you lose the threading that works to move the kernels quickly along the tube. In a nutshell - just keep the straw mod for the very end of the dispensing tube, and you will get both the benefit of fast movement of the powder and smooth dispensing.
I use a ferrite choke on the power cords for the RCBS Chargemaster 1500, and I locate the plug (transformer) far from the units (pretty much far as the cord reaches).
I do this to try to reduce any Radio Frequency Interference with the scales. My (possibly incorrect) thinking is that wires are essentially antennas, and can pick up RFI - an inexpensive ferrite choke make help avoid this issue, so I pulled some off unused electronics in my closet and use them for my scales.