no the longer legs wont make any difference. i have tried running these vertically without legs on a metal bakers rack and the temp differences were the same. also longer legs means less stability because the center of gravity will be higher and no one wants their miner tipping over. longer legs means a wider base to bring back sturdiness and will use more PLA material and when there is no benefit to longer legs that equals uneeded waste. not to mention the cost of the kits will go up to offset the time and material needed to print them up. a box fan wont help air flow either because unlike the s5's these units are enclosed completely so running a box fan will just waste more electricity and you wont see really any gain from doing that.....not with the s5+/s7/s9 miners at least since they all use the same design.
Sooooooooo no one wants to order any vertical leg kits for their miners ehh?? shoot me a pm if you do