So, we ran our second session, loosely based on the short story "free fall" set in nearby hollywood.
There was a clearly important skill check, which the character failed. Because it was so important, I suggested that the player might want to go all in, spend a point of edge for reroll, and spend a 2nd point of edge for advantage on the reroll. 2nd failure!
Can the player spend a third point of edge for a second reroll? Google says there's a "one expenditure" rule that I think I'm going to adopt regardless of whether it's in the book, that says "Characters can only have one expenditure of Edge per action or test." and that it might be found on page 60 or 77. Needless to say, I can't find this on either of the pages, I've read the edge rules on 77 with no solution, and the pdf returns no search results for "expenditure".
1) can I buy a reroll and then buy advantage on the reroll? When buying advantage, it says it needs to be purchased before rolling dice. In 40k the roll has already happened, and "roll" is a different keyword than "reroll".
2) can I buy a re-reroll? I can't find anything that says I shouldn't be able to, but edge is admittedly a new concept that I don't remember from 2nd.
The players are having a great time and we all love the flashback mechanic.
Edit: There's a distinct implication, not spelled out, that when the players roll a legwork edge pool of double digits, we might sit around rerolling a dozen times, breaking the flow of the game. I didn't want to anchor the answers I was getting back, but it doesn't feel right to me to spam rerolls until you get success, sitting there watching one person reroll for a couple of minutes.