Hey, if you're wondering new game any% for 3DS/ PC is timed using the in-game timer and thus an auto splitter wouldn't really be needed. For the Switch version, it's timed using RTA from the confirmation of a new file to the final hit of Nova 2; this also happens to be about equal to the in-game timer for the run.

Long story short, for any% an auto-splitter isn't really needed but if you would like to adapt it to time for any%, more power to you. I'm sorry to say that I can't really help in this regard because I know nothing about making an auto-splitter program.

Best of luck and I hope you do well in future runs!