I can see several ways in which having fixed roll files could be useful:
Small roll files used for testing, to snapshot the results of a strategy
After incorporating a simulation module (see #14), users could test strategies against some standard roll files
For users who don't believe in the randomness of some computers. Other craps software offer rolls with different randomization schemes, e.g. Wincraps https://cloudcitysoftware.com/brfiles.htm.
I can see several ways in which having fixed roll files could be useful: