Feats for a poison based build

[Skullruss]

I've been looking dead ahead at the Poisoner feat, but it seems lackluster, given that it only denies resistance and not immunity, though the bonus action application of poison sounds rather useful on its own. The poison for 50gp seems nice, but I feel like by the time 50gp is accessible that won't be very useful. Is this feat useful, in your opinions? Are there other feats that would be useful for a low-level arcane trickster rogue to use for a poison-centric build? For reference, we're level 4 now, just hit level 4 and I was looking for a useful feat to take. If there's nothing solid for the poison-centric side, what would you guys recommend for just a standard arcane trickster rogue in that case? I was kinda eyeing the Lucky and Piercer feats, given that I'm using mostly piercing weapons and rerolls are ALWAYS nice.

[Kane0]

Perhaps the UA alchemist feat? Ask the DM if you can use it to increase the potency of poisons rather than potions, or craft them cheaper/faster.

Otherwise some way of getting a good supply of poison you can milk, like expertise in animal handling, a beastmaster dip/friend or venomous creature sidekick