3e tried to create an unified mechanism for all poisons, whatever their real effect. It's somewhat dumb and unflavorful.
Sure, they can use the condition track for poison. But it will be only simpler than 3e.
What I would like is : no generic poison rules. Why need such a thing ?
If you have, let say, 12 poisons in the DMG, 4 lines to descript each one, you just need two pages or so for all of them.
Poison A makes you loose HP per round/minute/hours as long as you don't succeed a saving throw
Poison B gives inflict you one permanent level on the condition track
Poison C forces you to make a fort saving throw every minutes or fall asleep. Its effects disappear after an hour
Etc...
Designates fun poisons, try to make them mildly realistic and different (poison F acts after 1 or 2 days ; poison J cause progressive paralysis etc...). It looks like 2e, but 3e was a non-sense.
Poison could be as varied as spells, IMHO.