I think all freighters should have something like this. With modern tech it should be quite possible to make it reliable.
We lost two good guys on an F27 at GCI due to an out of trim aircraft and there have been quite a number of others. Fine Air at Miami for one.
I think the bean counters don't like it as you would have quite a few returns to stand for just a minor error.
Actually why not on pax a/c as well. There has been a duscussion about standard weights for pax lately. This would solve the problem.
Once the aircraft is rolling the oleo pressure is directly proportional to the weight being supported, simple sums comes up with a Go/NoGo answer.
Sorry for thread drift, but this bugged me for all my years in air cargo.