This is a really interesting discussion, and I agree it should be covered in the 'Dry Rock' cycling guide.
There are a couple of things to note - which others have pointed out above - and should be updated in the cycling guide:
1) Its likely better to include some non-mined dry rock in your tank - this will supply the PO4
2) Its better yet to include some live rock - even if a couple of pieces in the overall mix of your rock
3) Dosing is an option but I would suspect (without evidence) is inferior to 1 & 2
Lastly:
4) It may be possible to mitigate some of these effects by adding significant coral frags after Nitrate cycle has been established. We're working on this in another thread and will hopefully be able to pull together some data which may demonstrate this use case.
There are a couple of things to note - which others have pointed out above - and should be updated in the cycling guide:
1) Its likely better to include some non-mined dry rock in your tank - this will supply the PO4
2) Its better yet to include some live rock - even if a couple of pieces in the overall mix of your rock
3) Dosing is an option but I would suspect (without evidence) is inferior to 1 & 2
Lastly:
4) It may be possible to mitigate some of these effects by adding significant coral frags after Nitrate cycle has been established. We're working on this in another thread and will hopefully be able to pull together some data which may demonstrate this use case.