Use a longer and more complex master password. You're welcome.
This has nothing to do with my usage.
255! vs 255! / (255 - 30)!
My math could be off though, i haven't work with factorials since i was in the university
With unknown size, cracking 30 characters takes time proportional to n^30 + n^29 + n^28 etc.
Cracking just 30 is proportional to n^30.
The difference is negligible. A percent or two.