The issue is that these runs could potentially still happen on Tempus. Players with low ping and consistent net may be able to do runs with them. Prep the run on local or something then go to Tempus and do it first time. Or fail around for a bit to seem less obvious then do the run.
Seems like plugin would get released and it wouldn't be long before someone modifies it or takes inspiration from it to do their make their own thing. While this isn't exactly a new idea to most jumpers, having something available online may spur on other cheaters to make their own based on his.
EDIT: After thinking about it a bit more, the only way I can see this working well is if it is a server-side enhancement. This way we can have online servers dedicated to these runs, or players can setup their own local servers to do offline runs. People who want to use this tool are probably clever enough to do a simple server setup on a local machine.
If it is a client-side plugin, then I'd say it has to somehow be offline only, OR there needs to be some automatic way to detect and kick players doing these runs on online servers. Even if there is some ridiculously obvious giveaway at the start/middle/end of a run (showing that it is TAS), if it needs to be spotted and reported manually, this would be horrible for jumping. From my biased perspective of running Tempus, this basically means having to manually verify every single run that gets made. People won't only use TAS to make perfect, WR-breaking runs, they will use it as well to make top-10 or even just PR beating times.