When someone toggles the Potions flag, players in the field are stuck with the infinite potion effect (In my case, the Speed potion). This could be 'abused' in a sense to gain infinite positive effects.

Also, it seems that the Poison effect doesn't work. I see it listed in /ps info (http://gyazo.com/f8bb06e1d4c7990b8350d4e54d970cf5) but I don't receive any effect while in the field (http://gyazo.com/a01a633682c9739501d1f1d4c45ec7bd).

I'm on spigot 1.8.3 currently, latest dev of PS. Thanks for any help in advance :)

I believe the first issue was fixed in a recent development build. As for you not getting the poison effect, that's a separate issue. Negate the permission node "preciousstones.manual.bypass.potions" for yourself and anyone else effected by this as a temporary fix as the bypass command doesn't seem to be working.