Personally I've always thought some of the current enchants could use some negatives
It's important to have the basic ones be pretty much completely positive or new players will shoot themselves in the foot (and I guess they could in theory pick up a risktaker as their first one, might need to change that), and also because it's a bit more fun if you're not always paying a pint of blood for an advantage.
But yea, I'm thinking most of the new enchant types going forward will be tradeoffs of some kind. Probably won't have randomized negatives as that could just lead to total-junk (TM) because no matter how good something is it can still get messed up by random negatives.
as well as there being a need for some just negative enchant types, lowering knockback and projectile speed come to mind (for the projectile speed one, my logic is that it would let me use an extremely slow moving creeping death as a way of slaughtering bosses)
Yea, that would be interesting, though the ability to create a stationary (or nearly so) creeping death shot could be a bit OP depending on boss type and position (but maybe that's rare enough where it's not OP, it's just clever tactics?).
But those aren't really "negative" in the gameplay sense, they're buffs where the math includes a minus sign; there's already some of those: resilient form reduces damage taken, cloak of shadows reduces enemy detection range, etc.
But yea, shot speed is one of those things where there's no "positive" direction;
usually you want higher values, but sometimes lower is better.