what should i do if i need more than 10k.
Since a subfile should never have more than a couple hundred records written to it, you should never need more than 10k.
You should never force a user to have to scroll through ten thousand records. And if you don’t want them scrolling that far, there is no reason to put all of those records in there at one time.
Use a page-at-a-time subfile instead.
You cannot have more than 9999 records in any subfile.