Hey! About your suggestion, I don't think it's necessary because in the 'Kits' section of the survival games there is an kit called Scout which gives you speed potions to aid the process of hunting down/escaping your opponents as well as that you can find ender-pearls in the chests which is convenient for you to escape. As well as that, as you stated, a potion for 30 seconds will be pretty much useless in skywars because by the time you've applied the potion during a fight, you'll already be killed. Moreover, you won't be able to escape that far in skywars due to bridging and the space of each island, unless you jump off the edge xD