Perhaps other A700 drivers could share their experiences on the cornerweights, I also have been using a 4 scale set up. I found out that getting reliable readings wasn't quite as straightforward as anticipated.
I used my kitchen surface, which is dead level, and ended up swapping the scales around continually and sanded the rubber feet to make sure the table heights of each scale were the same, so if you move them to different positions the read as they should. Then I realised that TC wheels are invariably out of true so if you spin the wheels you get completely different readings. And don't weigh the same either, further corrupting the readings. I bought a set of Hudy set up wheels and repeated the process. These do seem to eliminate the errors.
Now I set the ride height and now that the errors have been dialled out I can use it to fine tune the preloads, and have been finding that the car pulls dead straight on hard power as soon as it hits the track, even though the wheels themselves are so inconsistent, I don't even have to use the trim anymore, which helps confidence.
Been running R311 F303 50.7/49.3 (w/o body) for a while, would like to try a more rearward bias like 52/48 but not sure if I have the skill to hold onto it