This is now available through LiveSplit without downloading it yourself. See "New Setup"
•There is a game bug where time spent in Stage 9 gets doubled on the save file, but does not affect the auto splitter. Proof video - This also displays why the final split is good where it is.
• If the autosplitter script is ever updated, you'll only need to restart LiveSplit to get that update.
• Should support any mode equally, except Boss Rush[RTA, unsupported].
• You should be able to split manually if you want, but I wouldn't recommend it, especially for the final split. If you manually split on the final hit, the timer may not match IGT because IGT can keep rolling a bit beyond that final hit, and that does count towards the game file's IGT. If you do split manually, you shouldn't have to worry about the script double-splitting in this case as it reads split number, stage, etc. to prevent such events.
• Final split is on credits start, which is the same moment the "Game Clear" flag gets written to the save file, indicating a complete run. This is the most reliable time to do the final split.
• This should perfectly match IGT down to the frame(which is slightly more accurate than the IGT displayed on the save screen).
If you want to reset on Stage 1, just use the 'Curse of the Moon' menu and it'll be much faster than exiting the game(the splitter works the same way). Abusing 'Curse of the Moon' IL time in later stages basically makes it a segmented run and shouldn't be allowed, but on Stage 1 this is fine because it's the same as starting a new run. Rules no longer allow using Curse of the Moon to start a run, despite it being the most convenient and most accurate. I don't agree with it, but... yeah.
• The timer will automatically reset if it has already split at least once and you enter Stage 1 on a fresh run(no IGT). To prevent unwanted resets, it will not reset in this situation if you just finished a run, but forgot to save/end your splits.
With this, you should be able to use 'Curse of the Moon' menu at any time and go back to Stage 1 to reset a run, which is faster than exiting the game. See above.
• This timer also starts up automatically in Boss Rush on Glutton Train, but only on Glutton Train, because it meets all the requirements for starting a normal run. To help this, it will automatically reset the splits if you enter the Boss Rush lobby and your current split is not the final(complete run, unsaved splits).
• This ASL checks for COTM.exe's MD5Hash to determine which version you're running, and if there is no match, it will default to the latest or most popular version.