Surface source reading method in openmc

Hi guys.
Again, I have a question about SSW/SSR.
I want to know suitable number of particles per 1 batch in SSR calculation.

If 1,000 of surface source was collected via SSW calc, should I use this value in multiples of 1,000?
If sources are randomly sampled in file, it doesn’t matter but I’ll use more than 1,000 and(or) more batches.
but if sources are read sequantially, I think particles/batch should be multiples of 1,000 In order to prevent bias due to the sources collected in the first place.

Thanks for your all replies.