Can a provisional patent application be filed within the 1 year grace period for after public disclosure, or does it need to be a non-provisional application?
Either a provisional or a non-provisional application can be used. But remember, any application is only as good as what it contains. If you take "provisional" to be "very sparse on depth and breadth" then it may not do the job. But it isn't the difference between provisional and non provisional, it is the difference between a complete discourse and a poor disclosure.