I don’t see that work. If “finite” is low and delays between them short, scammers will make the effort to go through all warnings.

If delays between warnings are long, the scammer will wait until one is shown and then sell the fake, and the buyer will only be warned when it’s too late.

If it’s high, the difference with “forever” is small, and you’ll still be annoyed.

Having a separate screen that shows the warning on demand or showing the warning only after a new sim is inserted might be the best option, but I fear too few customers would know about it.