This works if you're recording to 1 folder (no subfolders in Filename Formatting). Create a .bat file with the following:
Code:
cd "C:\Users\USERNAME\Videos\OBS"
del *.mkv
Change path as necessary.
Use Windows Task Schedule to create a task that runs that "program" once per day, ex: 11:00:00 AM
Set the task to once an hour indefinitely (you can change that to 5, 10, 15 or 30 minutes)
Please keep in mind the file might still be saving after you stop recording and the time it takes to remux the file. Don't stop recording 3 seconds before the batch file runs to delete the MKV. They are deleted deleted, not in the Recycle Bin.