All of the above would be great, especially if we got to decide which info to toggle on/off. If there could only be 1 addage I'd LOVE it to be recent form figures. I'd even prefer that in place of jockey names! as horse form is of greater importance to me. But having them both on option would just about complete the software.
I think it might be a lot of work to reduce the popup list by adding the ability for the user to select the choices of interest in settings. It might be more feasible to try to add the horse's form just beneath the horse name in the grid (where the jockey is shown), perhaps with an option to choose whether the show the form or jockey or both. That would also make the information in full view without having to hover over each horse name just to see the form amongst all the other data. Does that sound useful? I'm not sure if I can do that yet, but it might work.