I believe I'm someone that falls in that 3 min window (I'll have to check which block is the 3 min cut off point), and for those who feel this is unfair if it were to be included in the proposal and pass, let me describe what happened to me.
I was ready right at the moment the countdown finished to purchase the bulk packs with 15% bonus. Realizing I could move a bit more SPS from HE to my SL account to better utilize the 15% bonus on a few dozen more packs, I went to another window to make this transfer, then I came back and processed my purchase.
At no point before I switched tabs, or after I came back did I see an active countdown of packs being sold that qualified for the promo. There was a tally, but it wasn't updating live from what I could see, as it was stuck on something like 125 packs sold which was there from right when the page popped up after the countdown. It only updated to over 500K packs sold after I purchased. I had no idea whether I had qualified for the promo or not until I looked up the block cutoff of block ******464 that was posted around.
Had I seen how fast they were moving I would have just done the 2 clicks of "500 packs + purchase" and not fussed around trying to make a larger purchase, and I'd have made it in. Or, had I seen that I missed the 500K promo pack cut off, I also just wouldn't have purchased any, and I'd probably instead bought a node with those funds... which I have obviously missed tranch 1 of now as my purchase funds are locked up until all of this is figured out.
Another thing that wasn't available which I hope the community might agree warrants allowing rewards up to 3 min in this case, is it would make sense for the sales window and calculator for total sps and vouchers required to be able to be filled out, so that at the right moment it's just a single click that's required. As alluded to in the post this would streamline it for everyone (abled and less abled) no matter how many packs they want to purchase, without confusion around the vouchers, and having enough funds immediately available.
Having been in previous Splinterlands promo releases, they've never gone this fast, so it wasn't expected which I hope adds to everyone's understanding of other people's frustration with what happened. If anyone here has ever been a part of the frenzied and often glitchy popular NFT releases you can experience on platforms like WAX, I'm sure you'd agree it would also be great if future Splinterlands releases DIDN'T end up going in that direction when possible, but since it did happen, hopefully you can understand how some of us by error, simple misunderstanding, etc, missed this release, and how we'd be grateful for the rewards to be extended to a 3 min window as proposed.