OK, so I don't really understand plugins at all, especially how to make/use my own, even if all the script is already given to me. Because of that, I ended up using a workaround of sorts.
Originally, since I'd been using parallel events anyhow (and the issue with the status being changed when the player loading a save or entering a new map thereby being bypassed), I was planning to just use $dataMap.disableDashing = true.
However, since I wanted to be able to switch that based on the current actor (using that parallel command I mentioned), and furthermore since I'm not certain that all of my maps in the future will have sprinting enabled, I couldn't just reenable Dashing with an actor swap.
My first thought was to have some kind of call that would refresh the map (using the potential problem as the solution), but I couldn't figure out how to make that work. If you know how to do that, I'd appreciate it, despite the fact that I have another workable solution now.
Basically, instead of disabling sprinting, I just slowed the actor down whenever they're active. So when the specific actor starts leading the party, the parallel event reduces their speed to 3 (2x slower), and when any other actor starts leading the party, the parallel event returns their speed to 4 (normal).
This means that the specific actor still feels slower (the problem dashing was causing), without having to figure out how to disable dashing. If you want more details on how I did that, I'll be happy to provide them, just let me know.
Thanks Caethyris for your suggestions, they really pointed me in the right direction even if I didn't end up using them in the end!