How fine to chop?

I have a 1:1 mix of peralite and peat. I have live sphagnum that I have been successful growing and want to chop some up to put on the peat, which I will then sow some seeds.


My questions are:
How fine do I chop the sphagnum moss?
Should I sow the seed when I chop the sphag and let them start at the same time or should I wait until the sphag starts?

Thanks in advance for you help.

the live LFS will outgrow your seedlings unless you constantly trim it back, which is what im having to do with my nep seeds. id chop it up as fine as you possibly can.